tag:theconversation.com,2011:/us/topics/periodic-table-23742/articlesPeriodic table – The Conversation2023-10-27T12:17:17Ztag:theconversation.com,2011:article/2161372023-10-27T12:17:17Z2023-10-27T12:17:17ZAsteroids in the solar system could contain undiscovered, superheavy elements<figure><img src="https://images.theconversation.com/files/555902/original/file-20231025-23-pgf5be.jpg?ixlib=rb-1.1.0&rect=52%2C30%2C4981%2C3426&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An illustration of an asteroid orbiting through space. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/illustration-of-an-asteroid-royalty-free-illustration/973895632?phrase=asteroid&adppopup=true">Mark Garlick/Science Photo Library via Getty Images</a></span></figcaption></figure><p>For centuries, the <a href="https://sciencenotes.org/when-were-the-elements-discovered-timeline-and-periodic-table/">quest for new elements</a> was a driving force in many scientific disciplines. Understanding an atom’s structure and the development of nuclear science allowed scientists to accomplish the old goal of <a href="https://www.merriam-webster.com/dictionary/alchemy">alchemists</a> – <a href="https://www.britannica.com/science/transmutation">turning one element into another</a>. </p>
<p>Over the past few decades, scientists in the <a href="https://www.lbl.gov/">United States</a>, <a href="https://www.helmholtz.de/en/about-us/helmholtz-centers/centers-a-z/centre/gsi-helmholtz-centre-for-heavy-ion-research/">Germany</a> and <a href="https://www.iaea.org/contact/joint-institute-for-nuclear-research-jinr">Russia</a> have figured out how to use special tools <a href="https://physicalsciences.lbl.gov/2023/10/16/berkeley-lab-to-test-new-approach-to-making-superheavy-elements/">to combine two atomic nuclei</a> and create new, <a href="https://doi.org/10.1146/annurev-nucl-102912-144535">superheavy elements</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A periodic table, with each group a different color." src="https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=327&fit=crop&dpr=1 600w, https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=327&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=327&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=411&fit=crop&dpr=1 754w, https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=411&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/555904/original/file-20231025-30-pcmast.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=411&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The heaviest element on the periodic table has 118 protons.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Periodic_table_%28JPEG_version%29.jpg">Licks-rocks/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>These heavy elements usually aren’t stable. Heavier elements <a href="https://www.energy.gov/science/doe-explainsprotons">have more protons</a>, or positively charged particles in the nucleus; some that scientists have created <a href="https://www.smithsonianmag.com/science-nature/when-will-we-reach-end-periodic-table-180957851/">have up to 118</a>. With that many protons, the electromagnetic repulsive forces between protons in the atomic nuclei overwhelm the attractive nuclear force that keeps the nucleus together. </p>
<p>Scientists have <a href="https://doi.org/10.1007/BF01172015">predicted for a long time</a> that elements with around 164 protons could have a relatively long <a href="https://www.britannica.com/science/half-life-radioactivity">half-life</a>, or even be stable. They call this the “<a href="https://www.eurekalert.org/news-releases/627973">island of stability</a>” – here, the attractive nuclear force is strong enough to balance out any electromagnetic repulsion. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A purple piece of machinery in a concrete room with metal boxes and cables coming off it." src="https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556194/original/file-20231026-23-l75f9c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Scientists at Lawrence Berkeley National Laboratory have constructed experiments that can weigh superheavy elements.</span>
<span class="attribution"><a class="source" href="https://science.osti.gov/np/Highlights/2019/NP-2019-08-c">Marilyn Chung, Lawrence Berkeley National Laboratory</a></span>
</figcaption>
</figure>
<p>Since heavy elements are difficult to make in the lab, <a href="https://scholar.google.com/citations?user=7GzPpUgAAAAJ&hl=en">physicists like me</a> have been looking for these elements everywhere, <a href="https://www.scientificamerican.com/article/the-quest-for-superheavy-elements-and-the-island-of-stability/">even beyond the Earth</a>. To narrow down the search, we need to know what sort of natural processes could produce these elements. We also need to know what properties they have, like their mass densities. </p>
<h2>Calculating density</h2>
<p>From the outset, my team wanted to figure out the mass density of these superheavy elements. This property could tell us more about how the atomic nuclei of these elements behave. And once we had an idea about their density, we could get a better sense of where these elements might be hiding. </p>
<p>To figure out the mass density and other <a href="https://doi.org/10.1007/BFb0116498">chemical properties</a> of these elements, my research team used a model that represents an atom of each of these heavy elements as a single, charged cloud. This model works well for large atoms, particularly metals that are laid out in a lattice structure.</p>
<p>We first <a href="https://doi.org/10.1140/epjp/s13360-023-04454-8">applied this model</a> to atoms with known densities and calculated their chemical properties. Once we knew it worked, we used the model to calculate the density of elements with 164 protons, and other elements in this island of stability. </p>
<p>Based on our calculations, we expect stable metals with atomic numbers around 164 to have densities between 36 to 68 g/cm<sup>3</sup> (21 to 39 oz/in<sup>3</sup>). However, in our calculations, we used a conservative assumption about the mass of atomic nuclei. It’s possible that the actual range is up to 40% higher. </p>
<h2>Asteroids and heavy elements</h2>
<p>Many scientists <a href="https://www.nationalgeographic.com/science/article/101209-asteroid-collisions-earth-gold-science-space">believe that gold</a> and other heavy metals were deposited on Earth’s surface after <a href="https://earthsky.org/earth/did-meteorites-bombard-earth-with-gold/">asteroids collided with the planet</a>. </p>
<p>The same thing could have happened with these superheavy elements, but super mass dense heavy elements sink into ground and are eliminated from near the Earth’s surface by the <a href="https://www.usgs.gov/news/science-snippet/earthword-subduction">subduction of tectonic plates</a>. However, while researchers might not find superheavy elements on Earth’s surface, they could still be in asteroids like the ones that might have brought them to this planet.</p>
<p>Scientists have estimated that some asteroids have mass densities greater than that of <a href="https://www.rsc.org/periodic-table/element/76/osmium">osmium</a> (22.59 g/cm<sup>3</sup>, 13.06 oz/in<sup>3</sup>), the densest element found on Earth. </p>
<p>The largest of these objects is asteroid 33, which is <a href="https://en.wikipedia.org/wiki/33_Polyhymnia">nicknamed Polyhymnia</a> and has a calculated density of 75.3 g/cm<sup>3</sup> (43.5 oz/in<sup>3</sup>). But this density might not be quite right, since it’s quite difficult to measure the mass and volume of far-away asteroids.</p>
<p>Polyhymnia isn’t the only dense asteroid out there. In fact, there’s a whole class of superheavy objects, including asteroids, which could contain these superheavy elements. Some time ago, I introduced the name <a href="https://doi.org/10.1103/PhysRevLett.110.111102">Compact Ultradense Objects, or CUDOs</a>, for this class. </p>
<p>In a study published in October 2023 in the <a href="https://doi.org/10.1140/epjp/s13360-023-04454-8">European Physical Journal Plus</a>, my team suggested some of the CUDOs orbiting in the solar system might still contain some of these <a href="https://www.youtube.com/watch?v=wj7BM6Jt-4I">dense, heavy elements</a> in their cores. Their surfaces would have accumulated normal matter over time and would appear normal to a distant observer.</p>
<p>So how are these <a href="https://doi.org/10.1103/RevModPhys.93.015002">heavy elements produced</a>? Some extreme astronomical events, like <a href="https://www.scientificamerican.com/article/how-star-collisions-forge-the-universes-heaviest-elements/">double star mergers</a> could be hot and dense enough to produce stable superheavy elements. </p>
<p>Some of the superheavy material could then remain on board asteroids created in these events. They could stay packed in these asteroids, which orbit the solar system for billions of years.</p>
<h2>Looking to the future</h2>
<p>The <a href="https://www.esa.int/Science_Exploration/Space_Science/Gaia_overview">Eurpoean Space Agency’s Gaia mission</a> aims to create the largest, most precise three-dimensional map of everything in the sky. Researchers could use these extremely precise results to <a href="https://doi.org/10.3847/1538-3881/ace52b">study the motion of asteroids</a> and figure out which ones might have an unusually large density.</p>
<p>Space missions are being conducted to collect material from the surfaces of asteroids and analyze them back on Earth. Both NASA and the <a href="https://global.jaxa.jp/">Japanese state space agency JAXA</a> have targeted low density near-Earth asteroids with success. Just this month, NASA’s <a href="https://science.nasa.gov/mission/osiris-rex/">OSIRIS-REx</a> mission brought back a sample. Though the sample analysis is just getting started, there is a very small chance it could harbor dust containing superheavy elements accumulated over billions of years. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diagram showing the Psyche spacecraft's approach to the asteroid, where it starts at Earth in the center and moves in a counterclockwise spiral to the top of the screen, where it arrives at the asteroid." src="https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/556232/original/file-20231026-29-oeel6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Psyche spacecraft has left Earth. It will use the gravitational field of Mars to carry it closer to the asteroid. It will then orbit the asteroid and collect data.</span>
<span class="attribution"><a class="source" href="https://www.jpl.nasa.gov/images/pia24930-psyches-mission-plan">NASA/JPL-Caltech</a></span>
</figcaption>
</figure>
<p>One mass-dense dust and rock sample brought back to Earth would be enough. <a href="https://science.nasa.gov/mission/psyche/">NASA’s Psyche mission</a>, which launched in October 2023, will fly to and sample <a href="https://www.smithsonianmag.com/smart-news/nasa-launches-mission-to-study-distant-asteroid-180983072/">a metal-rich asteroid</a> with a greater chance of harboring superheavy elements. More asteroid missions like this will help scientists better understand the properties of asteroids orbiting in the solar system.</p>
<p>Learning more about asteroids and exploring potential sources of superheavy elements will help scientists continue the century-spanning quest to characterize the matter that makes up the universe and better understand how objects in the solar system formed. </p>
<p><em>Evan LaForge, an undergraduate student studying physics and mathematics, is the lead author on <a href="https://doi.org/10.1140/epjp/s13360-023-04454-8">this research</a> and helped with the writing of this article, along with Will Price, a physics graduate student.</em></p><img src="https://counter.theconversation.com/content/216137/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Johann Rafelski does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Scientists have been searching Earth’s surface for superheavy elements too difficult to make in the lab, but now, many are looking to the skies instead.Johann Rafelski, Professor of Physics, University of ArizonaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1695622021-11-04T16:05:35Z2021-11-04T16:05:35ZYour smile’s cosmic history: we discovered the origin of fluoride in early galaxies<figure><img src="https://images.theconversation.com/files/430101/original/file-20211103-25-10jnbn2.jpg?ixlib=rb-1.1.0&rect=0%2C74%2C958%2C834&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Flouride is created by Wolf–Rayet stars, here seen in the Milky Way by the Hubble Space Telescope. </span> <span class="attribution"><span class="source">Nasa/Judy Schmidt</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Look at the ingredients on a tube of toothpaste and you will probably read something like “contains sodium fluoride”. Fluoride, as you probably know, is important for healthy teeth. <a href="https://www.nature.com/articles/news040119-8">It strengthens enamel</a>, the hard, protective layer around a tooth, and so helps prevent cavities. </p>
<p>You may not think too deeply about toothpaste. But like all things on Earth, from the majestic to the mundane, fluoride - and the story of a smile - has a cosmic origin. Now, my colleagues and I have <a href="https://www.nature.com/articles/s41550-021-01515-9">published a paper in Nature Astronomy</a> that sheds some light on it.</p>
<p>Virtually all natural elements were formed long ago in the history of the universe. Hydrogen is the oldest element: it formed very shortly after the big bang, about 14 billion years ago. Within a few minutes of the big bang, the light elements <a href="https://w.astro.berkeley.edu/%7Emwhite/darkmatter/bbn.html">helium, deuterium and lithium</a> were also formed in a process called <a href="https://w.astro.berkeley.edu/%7Emwhite/darkmatter/bbn.html">big bang nucleosynthesis</a>. Since then, nearly every other element has been forged in processes associated with the <a href="https://theconversation.com/piercing-the-mystery-of-the-cosmic-origins-of-gold-88880">life and death of stars</a>. But those stars were not always around. </p>
<figure class="align-center ">
<img alt="Image of toothpaste." src="https://images.theconversation.com/files/430041/original/file-20211103-25-f9f941.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430041/original/file-20211103-25-f9f941.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430041/original/file-20211103-25-f9f941.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430041/original/file-20211103-25-f9f941.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430041/original/file-20211103-25-f9f941.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430041/original/file-20211103-25-f9f941.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430041/original/file-20211103-25-f9f941.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Do you consider the cosmic origins of your toothpaste when brushing your teeth?</span>
<span class="attribution"><span class="source">Pixabay</span></span>
</figcaption>
</figure>
<p>We still don’t know exactly when the first stars ignited in the universe, but it probably didn’t happen for about <a href="https://theconversation.com/after-our-universes-cosmic-dawn-what-happened-to-all-its-original-hydrogen-65527">100 million years or so after the big bang</a>. Before this, the universe was filled with a fog of hydrogen, mingled with the mysterious, invisible substance astronomers call dark matter. This fog was not smooth, but rippled - slightly denser in some places. It was these regions that started to contract, or “collapse”, due to gravity, to form the first galaxies. Where the gas got dense enough, stars ignited and lit up the universe.</p>
<p>The following few billion years was a time of rapid growth: the rate of star formation in the universe rose sharply until it reached a peak, 8 to 10 billion years ago. Ever since that “cosmic noon”, the overall rate of star formation in the universe has been in decline. That’s why astronomers are so interested in the early phases of the history of the cosmos: what happened then shaped what we see around us today. </p>
<p>While we have quite a lot of information about how the growth of galaxies “ramped up” in terms of their star formation, we have relatively little insight into their chemical evolution at the earliest times. This is important because, as stars live and die, the elements they produce become dispersed throughout a galaxy and beyond. Many years later, some of those elements can form new planets like ours. </p>
<h2>Rapid evolution</h2>
<p>We observed a distant galaxy called NGP-190387 with the <a href="https://www.almaobservatory.org/en/home/">Atacama Large Millimetre/sub-millimetre Array</a> (Alma) - a telescope that detects light with a wavelength of around one millimetre. This allows us to see the light emitted by cold dust and gas in distant galaxies. The data revealed something unexpected: a dip in the light at a wavelength of exactly 1.32 millimetres. This corresponds exactly to the wavelength at which the molecule hydrogen fluoride (HF), comprising a hydrogen atom and fluorine atom, absorbs light (taking into account a shift in wavelength that happens due to the universe’s expansion). The deficit of light implies the presence of clouds of hydrogen fluoride gas in the galaxy. This light has taken over 12 billion years to reach us, and we see the galaxy as it was when the universe was 1.4 billion years old.</p>
<p>This is exciting, because it provides information about how galaxies first became enriched with chemical elements shortly after they first formed. We can see that even at this early time, NGP-190387 had a high abundance of fluorine. Although we have observed other elements in distant galaxies, such as carbon, nitrogen and oxygen, this is the first time fluorine has been detected in a star-forming galaxy at such a distance. The greater the variety of elements we can observe in early galaxies, the better our understanding of the process of chemical enrichment at that time.</p>
<p>We know that fluorine can be produced in different ways: for example, in star explosions called supernovas and in certain <a href="https://en.wikipedia.org/wiki/Asymptotic_giant_branch">“asymptotic giant branch”</a> stars - red supergiant stars nearing the end of their life, having burned most of the hydrogen and helium in their cores and now swollen in size. </p>
<p>Models of how elements form in stars and in supernovae can tell us how much fluorine we should expect from these sources. And we found that the abundance of fluorine was too high in NGP-190387 to be explained by supernovas and asymptotic giant branch stars alone. An extra source was needed, and this is probably another type of star called a <a href="https://astronomy.swin.edu.au/cosmos/w/wolf-rayet+star">Wolf-Rayet</a>. Wolf-Rayet stars are quite rare – there are only a few hundred catalogued in the Milky Way, for example. But they are extreme. </p>
<figure class="align-center ">
<img alt="The Hubble Ultra Deep Field" src="https://images.theconversation.com/files/430034/original/file-20211103-27-o51gsc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430034/original/file-20211103-27-o51gsc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430034/original/file-20211103-27-o51gsc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430034/original/file-20211103-27-o51gsc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430034/original/file-20211103-27-o51gsc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430034/original/file-20211103-27-o51gsc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430034/original/file-20211103-27-o51gsc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ancient galaxies seen by the Hubble Space Telescpope.</span>
<span class="attribution"><span class="source">NASA/ESA</span></span>
</figcaption>
</figure>
<p>Wolf-Rayet stars are a phase in the lifecycle of very massive stars – with more than ten times the mass of our Sun. Approaching the end of their short life, these stars burn helium in their cores, and are millions of times more luminous than the Sun. Unusually, Wolf-Rayet stars have lost their envelope of hydrogen via powerful winds, leaving the helium core exposed. They will eventually explode in dramatic core-collapse supernova explosions. When we added the amount of fluorine expected from Wolf-Rayet stars to our model, we could finally account for the dip in light from NGP-190387. </p>
<p>This adds to a growing body of evidence that shows that the growth of galaxies was surprisingly fast-paced in the early universe: a frenzy of star formation and chemical enrichment. Those processes lay the foundations for the universe we see around us today, and this work provides new insight into the detailed astrophysics at play, over 12 billion years ago. </p>
<p>But perhaps the main take away is that it shows that the story of your smile is a tale as old as time.</p><img src="https://counter.theconversation.com/content/169562/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Geach receives funding from The Royal Society and the Science and Technology Facilities Council. </span></em></p>Tracing the cosmic origin of toothpaste, scientists got a glimpse into the surprising chemistry of early galaxies.James Geach, Professor of Astrophysics and Royal Society University Research Fellow, University of HertfordshireLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1544472021-02-03T16:09:57Z2021-02-03T16:09:57ZEinsteinium: 100 years after Einstein’s Nobel Prize, researchers reveal chemical secrets of element that bears his name<figure><img src="https://images.theconversation.com/files/382226/original/file-20210203-21-6vkxsw.jpg?ixlib=rb-1.1.0&rect=42%2C26%2C938%2C683&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Albert Einstein photographed on a trip to America in the wake of his Nobel prize-winning discoveries.</span> <span class="attribution"><a class="source" href="https://picryl.com/media/albert-einstein-washington-dc">Harris & Ewing/PICRYL</a></span></figcaption></figure><p>A century ago, an upstart German physicist by the name of Albert Einstein turned the scientific world on its head with his discovery of the photoelectric effect, which proved light to be both a particle and a wave. <a href="https://www.nobelprize.org/prizes/physics/1921/einstein/facts/">Awarded the</a> 1921 Nobel prize in physics for his work, Einstein would later contribute to theories related to nuclear fusion and fission – arguably paving the way for the invention and detonation of nuclear weapons, as well as nuclear energy.</p>
<p>And so, when elements previously unknown to science were discovered in the chemical debris of a nuclear explosion 69 years ago, it was fitting that scientists named what they found after the great physicist – adding “<a href="https://www.rsc.org/periodic-table/element/99/einsteinium">einsteinium</a>” to the periodic table. </p>
<p>Now, 100 years after Einstein’s Nobel prize win, chemists have finally been able to peer into the chemical behaviour of this elusive, highly radioactive element. What they’ve learned could help scientists further expand our understanding of the periodic table – including elements that are yet to be added to it.</p>
<h2>Explosive findings</h2>
<figure class="align-right ">
<img alt="A blue glowing vial of a chemical" src="https://images.theconversation.com/files/382276/original/file-20210203-15-1jxhhxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/382276/original/file-20210203-15-1jxhhxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=867&fit=crop&dpr=1 600w, https://images.theconversation.com/files/382276/original/file-20210203-15-1jxhhxv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=867&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/382276/original/file-20210203-15-1jxhhxv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=867&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/382276/original/file-20210203-15-1jxhhxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1090&fit=crop&dpr=1 754w, https://images.theconversation.com/files/382276/original/file-20210203-15-1jxhhxv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1090&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/382276/original/file-20210203-15-1jxhhxv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1090&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">300 micrograms of einsteinium.</span>
</figcaption>
</figure>
<p>Einsteinium (Es) is the 99th element in the periodic table. It was first discovered in 1952 when a thermonuclear device dubbed “Ivy Mike” was detonated on the island of Elugelab in the Pacific Ocean (now part of the Marshall Islands). Ivy Mike’s detonation was the first demonstration of a hydrogen bomb. Such a blast creates four times more energy than nuclear fission bombs (like those dropped on Japan in 1945) and four million times more energy than the burning of a similar amount of coal.</p>
<p>It was in the fallout from Ivy Mike’s explosion, amid the chemical debris, that atomic number 99 was found for the first time. Only about 200 atoms of this element were detected, which shows just how scarce it is. It took nine years of painstaking work for scientists to be able to synthesise element 99 in a lab, <a href="https://link.springer.com/chapter/10.1007%2F1-4020-3598-5_12">which they achieved in 1961</a>.</p>
<p>The team of researchers who made the discovery thought about naming the element “pandamonium”, since the project team behind Ivy Mike had operated under the acronym “PANDA”. But in the end, they decided to honour Albert Einstein. </p>
<figure class="align-center ">
<img alt="A large mushroom cloud captured on old film cameras" src="https://images.theconversation.com/files/382203/original/file-20210203-17-1481lh9.jpg?ixlib=rb-1.1.0&rect=4%2C8%2C2849%2C2229&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/382203/original/file-20210203-17-1481lh9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=471&fit=crop&dpr=1 600w, https://images.theconversation.com/files/382203/original/file-20210203-17-1481lh9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=471&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/382203/original/file-20210203-17-1481lh9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=471&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/382203/original/file-20210203-17-1481lh9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=591&fit=crop&dpr=1 754w, https://images.theconversation.com/files/382203/original/file-20210203-17-1481lh9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=591&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/382203/original/file-20210203-17-1481lh9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=591&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The blast from the Ivy Mike atmospheric nuclear test, photographed on November 1 1952.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/w/index.php?curid=19280560">The Official CTBTO Photostream/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Too hot to handle</h2>
<p>Perhaps unsurprisingly, very little has been known about einsteinium. An element birthed in a thermonuclear blast, it’s incredibly hard to experiment with due to its extreme radioactivity. Not only is it literally too hot to handle – one gram of einsteinium produces 1,000 watts of energy – it also emits harmful gamma rays, so working with the element requires researchers to wear protective gear at all times.</p>
<p>What’s more, einsteinium’s most commonly occurring form (called Es-253, based on the number of neutrons in the atom’s nucleus) has a <a href="https://www.radioactivity.eu.com/site/pages/Radioactive_Half_life.htm">half-life</a> of only 20 days. That means that, after 20 days, einsteinium decays by half. After a couple of months, the tiny quantities of the element that scientists are able to work with practically disappear.</p>
<p>So it’s no wonder that it’s taken nearly 70 years for scientists to get to grips with this element. But now, a team from the Lawrence Berkeley National Laboratory and the University of California at Berkeley have managed to pin down enough einsteinium to run some basic tests on the element – breaking new ground in experimental chemistry and fundamental science.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/five-chemistry-inventions-that-enabled-the-modern-world-42452">Five chemistry inventions that enabled the modern world</a>
</strong>
</em>
</p>
<hr>
<p>In <a href="https://www.nature.com/articles/s41586-020-03179-3">their paper</a>, the researchers explain how they managed to use just 200 nanograms of Es-254 (a rare form of einsteinium with a half-life of 275.5 days) to run their experiments. A nanogram is just one billionth of a gram, so these experiments took place on an incredibly small scale.</p>
<h2>Einsteinium chemistry</h2>
<p>Performing chemistry with einsteinium for the first time, the research team managed to synthesise a chemical compound that included the element in order to examine how it might interact with other elements in a compound. This was done under the <a href="https://www-ssrl.slac.stanford.edu/">Stanford Synchrotron Radiation Lightsource</a>, which beams high-energy light at chemical compounds to enable their structure to be exposed. You can think of this method as similar to how silhouettes are formed – but on an atomic scale.</p>
<p>One big finding was the bond distances between einsteinium atoms and other atoms around it – like carbon, oxygen and nitrogen. Knowing einsteinium’s bond distances for the first time means we can predict what other combinations of compounds featuring einsteinium will look like – adding entirely new combinations to our current knowledge of chemistry. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/382255/original/file-20210203-15-c6cu1m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="The periodic table, in colour" src="https://images.theconversation.com/files/382255/original/file-20210203-15-c6cu1m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/382255/original/file-20210203-15-c6cu1m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=385&fit=crop&dpr=1 600w, https://images.theconversation.com/files/382255/original/file-20210203-15-c6cu1m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=385&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/382255/original/file-20210203-15-c6cu1m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=385&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/382255/original/file-20210203-15-c6cu1m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=484&fit=crop&dpr=1 754w, https://images.theconversation.com/files/382255/original/file-20210203-15-c6cu1m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=484&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/382255/original/file-20210203-15-c6cu1m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=484&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The periodic table. Einsteinium features on the bottom row under ‘Es’.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/periodic-table-elements-colorful-vector-illustration-786893179">Humdan/Shutterstock</a></span>
</figcaption>
</figure>
<p>Crucially, the researchers also managed to determine the valence state of einsteinium. An atom’s valence controls how many other atoms it can bond to. This quantity is of fundamental importance in chemistry, determining the shape and size of the building blocks from which the universe is made. Einsteinium also happens to lie at an ambiguous position on the periodic table, between elements with different valences, so establishing its valence was also important for understanding its position in the table. </p>
<p>Einsteinium is currently the heaviest chemical element that can be examined in this way – so it’s exciting for chemists that new ground has been broken by this recent paper. The challenge facing future chemists is to try to synthesise heavier elements in similarly measurable quantities, revealing more about the chemicals that make up our world.</p>
<p><em>This article was amended on February 17, 2021 to clarify the definition of valence and to make clear that einsteinium’s valence helps us understand, not organise, its position in the periodic table.</em></p><img src="https://counter.theconversation.com/content/154447/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert A Jackson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The element was discovered in the fallout of a thermonuclear blast.Robert A Jackson, Reader, School of Chemical and Physical Sciences, Keele UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1508812020-11-26T14:03:24Z2020-11-26T14:03:24ZPeriodic table: scientists propose new way of ordering the elements<figure><img src="https://images.theconversation.com/files/371487/original/file-20201126-23-1ltgmk7.jpg?ixlib=rb-1.1.0&rect=34%2C17%2C3736%2C2115&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/camera-flies-through-periodic-table-on-718141813">Alexey Godzenko/Shutterstock</a></span></figcaption></figure><p>The periodic table of the elements, principally created by the Russian chemist, <a href="https://www.famousscientists.org/dmitri-mendeleev/">Dmitry Mendeleev</a> (1834-1907), celebrated its <a href="https://iypt2019.org">150th anniversary</a> last year. It would be hard to overstate its importance as an organising principle in chemistry – all budding chemists become familiar with it from the earliest stages of their education. </p>
<p>Given the table’s importance, one might be forgiven for thinking that the ordering of the elements were no longer subject to debate. However, two scientists in Moscow, Russia, have recently published a <a href="https://www.chemistryworld.com/news/new-ordering-of-elements-could-help-find-materials-with-promising-properties/4012751.article">proposal for a new order</a>.</p>
<p>Let’s first consider how the periodic table was developed. By the late 18th century, chemists were clear about the difference between an element and a compound: elements were chemically indivisible (examples are hydrogen, oxygen) whereas compounds consisted of two or more elements in combination, having properties quite distinct from their component elements. By the early 19th century, there was <a href="https://www.britannica.com/biography/John-Dalton/Atomic-theory">good circumstantial evidence</a> for the existence of atoms. And by the 1860s, it was possible to list the known elements in order of their relative atomic mass – for example, hydrogen was 1 and oxygen 16. </p>
<p>Simple lists, of course, are one-dimensional in nature. But chemists were aware that certain elements had rather similar chemical properties: for example lithium, sodium and potassium or chlorine, bromine and iodine. Something seemed to repeat and by placing chemically similar elements next to each other, a two-dimensional table could be constructed. The periodic table was born.</p>
<p>Importantly, Mendeleev’s periodic table had been derived empirically based on the observed chemical similarities of certain elements. It would not be until the early 20th century, after the structure of the atom had been established and following the development of quantum theory, that a theoretical understanding of its structure would emerge. </p>
<p>Elements were now ordered by atomic number (the number of positively charged particles called protons in the atomic nucleus), rather than by atomic mass, but still also by chemical similarities. But the latter now followed from the arrangement of electrons repeating in so-called “shells” at regular intervals. By the 1940s, most textbooks featured a periodic table similar to ones we see today, as shown in the figure below.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=318&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=318&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=318&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=400&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=400&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=400&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Today’s periodic table.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Simple_Periodic_Table_Chart-en.svg">Offnfopt/Wikipedia</a></span>
</figcaption>
</figure>
<p>It would be understandable to think that this would be the end of the matter. Not so, however. A simple search of the internet will reveal <a href="https://theconversation.com/the-periodic-table-is-150-but-it-could-have-looked-very-different-106899">all sorts of versions</a> of the periodic table. There are short versions, long versions, circular versions, spiral versions and even three-dimensional versions. Many of these, to be sure, are simply different ways of conveying the same information but there continue to be disagreements about where some elements should be placed.</p>
<p>The precise placement of certain elements depends on which particular properties we wish to highlight. Thus, a periodic table which gives primacy to the electronic structure of atoms will differ from tables for which the principal criteria are certain chemical or physical properties. </p>
<p>These versions don’t differ by much, but there are certain elements – hydrogen for example – which one might place quite differently according to the particular property one wishes to highlight. Some tables place hydrogen in group 1 whereas in others it sits at the top of group 17; some tables even have it <a href="https://upload.wikimedia.org/wikipedia/commons/f/f0/IUPAC_Periodic_Table_modified.PNG">in a group on its own</a>.</p>
<p>Rather more radically, however, we can also consider ordering the elements in a very different way, one which does not involve atomic number or reflect electronic structure – reverting to a one-dimensional list. </p>
<h2>New proposal</h2>
<p>The latest attempt to order elements in this manner <a href="https://pubs.acs.org/doi/abs/10.1021/acs.jpcc.0c07857">was recently published in the Journal of Physical Chemistry</a> by scientists <a href="https://scholar.google.ru/citations?user=0Hv62DAAAAAJ&hl=en">Zahed Allahyari</a> and <a href="https://msc.skoltech.ru/artemoganov">Artem Oganov</a>. Their approach, <a href="https://www.sciencedirect.com/science/article/abs/pii/0038109884907658">building on the earlier work of others</a>, is to assign to each element what’s called a Mendeleev Number (MN). There are several ways to derive such numbers, but the latest study uses a combination of two fundamental quantities which can be measured directly: an element’s atomic radius and a property called <a href="https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/Atomic_and_Molecular_Properties/Electronegativity#:%7E:text=Electronegativity%20is%20a%20measure%20of,the%20least%20electronegative%20at%200.7.">electronegativity</a> which describes how strongly an atom attracts electrons to itself. </p>
<p>If one orders the elements by their MN, nearest neighbours have, unsurprisingly, rather similar MNs. But of more use is to take this one step further and construct a two-dimensional grid based on the MN of the constituent elements in so called “binary compounds”. These are compounds composed of two elements, such as sodium chloride, NaCl. </p>
<p>What is the benefit of this approach? Importantly, it can help to predict the properties of binary compounds that haven’t been made yet. This is useful in the search for new materials that are likely be needed for both future and existing technologies. In time, no doubt, this will be extended to compounds with more than two elemental components.</p>
<p>A good example of the importance of the search for new materials can be appreciated by considering the periodic table shown in the figure below. This table illustrates not only the relative abundance of the elements (the larger the box for each element, the more of it there is) but also highlights potential supply issues relevant to technologies that have become ubiquitous and essential in our daily lives. </p>
<figure class="align-center ">
<img alt="Image of the periodic table showing element abundance." src="https://images.theconversation.com/files/371297/original/file-20201125-13-1l8n7ne.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/371297/original/file-20201125-13-1l8n7ne.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/371297/original/file-20201125-13-1l8n7ne.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/371297/original/file-20201125-13-1l8n7ne.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/371297/original/file-20201125-13-1l8n7ne.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/371297/original/file-20201125-13-1l8n7ne.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/371297/original/file-20201125-13-1l8n7ne.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Period table showing the relative abundance of elements.</span>
<span class="attribution"><span class="source">European Chemical Society/wikipedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Take mobile phones, for instance. All of the elements used in their manufacture are identified with the phone icon and you can see that several required elements are becoming scarce – their future supply is uncertain. If we are to develop replacement materials which avoid the use of certain elements, the insights gained from ordering elements by their MN may prove valuable in that search.</p>
<p>After 150 years, we can see that periodic tables are not just a vital educational tool, they remain useful for researchers in their quest for essential new materials. But we should not think of new versions as replacements for earlier depictions. Having many different tables and lists only serves to deepen our understanding of how elements behave.</p><img src="https://counter.theconversation.com/content/150881/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nick Norman does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New research suggests ordering the elements by atomic radius and ability to attract electrons.Nick Norman, Professor of Chemistry, University of BristolLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1300872020-05-14T12:04:36Z2020-05-14T12:04:36ZA new type of chemical bond: The charge-shift bond<figure><img src="https://images.theconversation.com/files/318398/original/file-20200303-66099-zi9ikj.jpg?ixlib=rb-1.1.0&rect=28%2C18%2C3054%2C1960&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A universe of chemical equations.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/science-old-chemistry-laboratory-seamless-pattern-276554942">Nikolayenko Yekaterina/Shutterstock.com</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/287050/original/file-20190806-84240-i26yzq.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/287050/original/file-20190806-84240-i26yzq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=171&fit=crop&dpr=1 600w, https://images.theconversation.com/files/287050/original/file-20190806-84240-i26yzq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=171&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/287050/original/file-20190806-84240-i26yzq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=171&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/287050/original/file-20190806-84240-i26yzq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=215&fit=crop&dpr=1 754w, https://images.theconversation.com/files/287050/original/file-20190806-84240-i26yzq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=215&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/287050/original/file-20190806-84240-i26yzq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=215&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em>The Abstract features interesting research and the people behind it.</em></p>
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<p><a href="https://www.researchgate.net/profile/John_Galbraith">John Morrison Galbraith</a> is an associate professor of chemistry at Marist College who studies chemical bonding, which is the process that holds atoms together to make molecules. </p>
<p><strong>What have you discovered?</strong></p>
<p>Did you take a chemistry course in high school? Did you think it was a boring static field filled with established facts that were determined a long time ago? I’ve done research that shows that the most fundamental of these established “facts,” the nature of the chemical bond, is now being questioned.</p>
<p>You have likely heard of covalent bonds, where electrons are shared between atoms, and ionic bonds, where electrons are completely transferred from one atom to another. But you probably don’t know about a third type of bond, discovered in the early 1990s by <a href="http://yfaat.ch.huji.ac.il/sason/sason.php">Sason Shaik</a> and <a href="http://pagesperso.lcp.u-psud.fr/hiberty/">Philippe Hiberty</a>: <a href="https://doi.org/10.1002/anie.201910085">the charge-shift bond</a>. I began working with them soon after. </p>
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<img alt="" src="https://images.theconversation.com/files/334505/original/file-20200512-82388-pcsd25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/334505/original/file-20200512-82388-pcsd25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=534&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334505/original/file-20200512-82388-pcsd25.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=534&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334505/original/file-20200512-82388-pcsd25.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=534&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334505/original/file-20200512-82388-pcsd25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=672&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334505/original/file-20200512-82388-pcsd25.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=672&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334505/original/file-20200512-82388-pcsd25.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=672&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The three types of chemical bonds. Red indicates electron-rich areas and blue indicates electron-deficient areas. (Top) the covalent bond in the hydrogen molecule showing electron build up in the bonding region between two indivual hydrogen atoms.</span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/334506/original/file-20200512-82388-1u9m9z6.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/334506/original/file-20200512-82388-1u9m9z6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=352&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334506/original/file-20200512-82388-1u9m9z6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=352&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334506/original/file-20200512-82388-1u9m9z6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=352&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334506/original/file-20200512-82388-1u9m9z6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=442&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334506/original/file-20200512-82388-1u9m9z6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=442&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334506/original/file-20200512-82388-1u9m9z6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=442&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The ionic bond in sodium chloride (table salt) showing electron transfer to the chlorine side (right).</span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
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<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/334507/original/file-20200512-82370-1hqwkkd.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/334507/original/file-20200512-82370-1hqwkkd.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/334507/original/file-20200512-82370-1hqwkkd.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/334507/original/file-20200512-82370-1hqwkkd.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/334507/original/file-20200512-82370-1hqwkkd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/334507/original/file-20200512-82370-1hqwkkd.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/334507/original/file-20200512-82370-1hqwkkd.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The charge-shift bond of the fluorine molecule showing electron depletion in the bonding region.</span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p><strong>What makes a charge-shift bond different?</strong></p>
<p>In charge-shift bonds, electrons are both shared and transferred at the same time. </p>
<p>That might sound a little crazy, but think of it like this: You know those movable walkways at airports? Suppose that for over 100 years, people thought that the only way to get from one point to another was to either stand on the moving walkway or walk alongside it. </p>
<p>Now suppose that someone realized that there is a third way to move: You can stand on the walkway and walk at the same time. The speed at which you move through the airport is not due to standing or walking, but a combination of both. </p>
<p><a href="https://doi.org/10.1038/nchem.327">Along with Shaik, Hiberty</a> and a handful of others around the world, <a href="https://doi.org/10.1021/jp049632o">I</a> <a href="https://doi.org/10.1021/acs.jpca.7b02988">have helped</a> show that charge-shift bonding is a broad phenomenon that happens between a variety of elements from across the periodic table. </p>
<p><strong>What inspired this discovery?</strong></p>
<p>Shaik and Hiberty were calculating the energy required to break a series of bonds using a method called valence bond theory. Chemistry is all about pattern recognition, and all of the bonds they studied fit a well-established pattern, except the bond between two fluorine atoms. Traditionally thought of as a purely covalent bond, this molecule didn’t behave like any other covalent bond. By trying to understand why, Shaik and Hiberty uncovered something completely unique. </p>
<p><strong>Why is it important?</strong></p>
<p>This is the first major change in the way chemists think about bonding in more than 100 years. Chemical bonding is at the heart of chemistry, so changing the way chemists think about bonding will change the entire field. </p>
<p><strong>How are charge-shift bonds applied in the real world?</strong></p>
<p>Synthetic <a href="https://www.ted.com/talks/cathy_mulzer_the_incredible_chemistry_powering_your_smartphone">materials</a> such as <a href="https://cen.acs.org/materials/2-d-materials/Method-irons-2-D-materials/96/i49">computer chips</a>, <a href="https://cen.acs.org/articles/88/i16/Plastic-Logic-Links-Germanys-Merck.html">plastics</a>, <a href="http://cenblog.org/just-another-electron-pusher/2011/09/the-science-of-beauty-cosmetic-chemistry/">cosmetics</a>, <a href="https://cen.acs.org/articles/93/web/2015/03/Motion-Powered-Fabric-Charge-Small.html">textiles</a> and <a href="https://cen.acs.org/articles/93/i43/Revolution-Medicines.html">medicines</a> come from making and breaking chemical bonds. </p>
<p>Therefore, insight into chemical bonding can inspire new materials with properties we have yet to imagine. We are already seeing chemists exploit the properties of charge-shift bonds to speed up chemical reactions and to understand the properties of industrial solvents.</p>
<p><strong>What is the coolest element of your new research?</strong></p>
<p>Chemistry is alive and constantly changing – that’s what first attracted me to the field. Charge-shift bonding challenges something so fundamental to the field that it is largely taken for granted. </p>
<p>The drama of sweeping theory change is in full effect here: The concept was introduced many years ago but not rapidly accepted; over time, diligent work by a handful of believers provided more support for the idea; and now it is gaining <a href="https://www.chemistryworld.com/features/what-is-a-bond/6983.article">widespread acceptance</a> due to verification through alternative <a href="https://doi.org/10.1021/ja053130m">experimental</a> and <a href="https://doi.org/10.1021/acs.jctc.6b00571">theoretical</a> means. </p>
<p>I also find it fascinating that most chemical processes can now be reliably modeled on a computer. I always liked chemistry for the knowledge it provided about how things work on the atomic scale. However, I never felt comfortable playing with beakers and hazardous chemicals. While chemistry is still a predominantly experimental science, today computers can direct those experiments while also providing a place for an experimentally challenged chemist such as myself.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p><img src="https://counter.theconversation.com/content/130087/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cottrell College Science Award for $35,718: Marist College, May 2006 - May 2008.
Merk AAAS Undergraduate Science Research Program Award: Marist College, Summer 2004 - Summer 2005.</span></em></p>The laws and principles of chemistry seem pretty set in stone. But as a chemist explains, the field is always evolving, including such fundamental principles as what is a chemical bond.John Morrison Galbraith, Associate Professor of Chemistry, Marist CollegeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1177512019-12-26T21:40:07Z2019-12-26T21:40:07ZThat’s a relief! We have a way to recover phosphorus from our urine<figure><img src="https://images.theconversation.com/files/301910/original/file-20191115-47161-1cnaml8.jpg?ixlib=rb-1.1.0&rect=49%2C917%2C5472%2C2703&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Phosphorus was first discovered by boiling down thousands of litres of urine.</span> <span class="attribution"><span class="source">Shutterstock/Lesterman</span></span></figcaption></figure><p><em>To mark the <a href="https://www.iypt2019.org/">International Year of the Periodic Table of Chemical Elements</a> we’re taking a look at some of the elements used by researchers in their work.</em></p>
<p><em>Today’s focus is phosphorus, an element that is vital for life but of limited supply. But we can recover phosphorus from a source that we all give away freely, every day, our urine.</em></p>
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<p><a href="http://www.rsc.org/periodic-table/element/15/phosphorus">Phosphorus</a>, number 15 on the periodic table, can be highly toxic and flammable and has been used in warfare as an <a href="https://www.reuters.com/article/us-afghanistan-phosphorus-facts-sb/factbox-key-facts-about-white-phosphorus-munitions-idUSTRE5471T620090508">incendiary device</a>, yet it is also essential for life.</p>
<p>As the famous science writer Isaac Asimov said in his 1974 book, <a href="https://books.google.com.au/books?id=t5EoAQAAMAAJ">Asimov on Chemistry</a>:</p>
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<p>Life can multiply until all the phosphorus has gone and then there is an inexorable halt which nothing can prevent.</p>
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Read more:
<a href="https://theconversation.com/titanium-is-the-perfect-metal-to-make-replacement-human-body-parts-115361">Titanium is the perfect metal to make replacement human body parts</a>
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<p>That’s because phosphorus is essential to all living organisms. It forms the backbone of our DNA as well as the molecule adenosine triphosphate (<a href="https://www.britannica.com/science/adenosine-triphosphate">ATP</a>) that is found in cells and captures chemical energy from the food we eat.</p>
<p>We have yet to find a single living being that does not require phosphorus to survive. But we don’t have an endless supply of phosphorus, and that’s where my research comes in.</p>
<h2>Demand grows for phosphorus</h2>
<p>Demand for phosphorus and nitrogen increased dramatically in the 20th century as it was found to play a crucial role in fertiliser used for growing crops. </p>
<p>In just over 50 years (between 1961 and 2014) fertiliser production increased <a href="https://ourworldindata.org/fertilizer-and-pesticides">tenfold</a> due to the so-called <a href="https://www.encyclopedia.com/plants-and-animals/agriculture-and-horticulture/agriculture-general/green-revolution">green revolution</a>.</p>
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<span class="caption">Phosphorus is an important ingredient in many fertilisers used to help grow our plant based foods.</span>
<span class="attribution"><span class="source">Shutterstock/otick</span></span>
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<p>This allowed for a worldwide increase in the agricultural production, particularly in the developing world, which was used to feed an ever-growing global population. </p>
<p>The high demand for nitrogen was met by ramping up a <a href="https://www.britannica.com/technology/Haber-Bosch-process">process</a> that captures nitrogen and hydrogen from fresh air and uses it to synthesise ammonia (the major nitrogen-based fertiliser). As the air in Earth’s atmosphere is made of <a href="https://climate.nasa.gov/news/2491/10-interesting-things-about-air/">78% nitrogen</a>, synthetic ammonia production was only limited by its cost. </p>
<p>But phosphorus is generally stored in solid or liquid form, and the cheapest way to cope with the high demand for phosphorus fertiliser was to extract if from phosphate rocks.</p>
<p>Phosphate rocks are a resource that is both limited and not equally distributed. The <a href="https://www.usgs.gov/centers/nmic/phosphate-rock-statistics-and-information">top five phosphate rocks holders</a> – Morocco and Western Sahara, China, Algeria, Syria, and Brazil – account for 84% of the world reserves. Australia holds just 1.6%.</p>
<p><iframe id="6Ll5J" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/6Ll5J/2/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>As phosphate rocks are a finite and non-renewable resource, the continuous extraction is causing <a href="https://www.sciencedirect.com/science/article/pii/S0959378015300765" title="A half-century of global phosphorus flows, stocks, production, consumption, recycling, and environmental impacts">uncertainties in our future supplies</a>.</p>
<h2>The wee supplies of phosphorus</h2>
<p>One solution is to look for other supplies of phosphorus, and that’s where you and I can play a role. Our urine is an excellent source of raw material for phosphorus. </p>
<p>Each one of us excretes up to <a href="https://www.sciencedirect.com/science/article/pii/S221334371830188X" title="Urine: The liquid gold of wastewater">half a kilogram</a> of phosphorus per year, just through our urine. This makes urine the <a href="https://www.sciencedirect.com/science/article/pii/S0045653511001925" title="Global potential of phosphorus recovery from human urine and feces">single largest</a> source of phosphorus from urban areas.</p>
<p>Back in the 17th century, the German chemist <a href="https://www.sciencehistory.org/distillations/hennig-brandt-and-the-discovery-of-phosphorus">Hennig Brandt</a> chose urine to isolate elemental phosphorus. In his experiment, he boiled hundreds of litres of urine down to a thick syrup until a red oil distilled up from it.</p>
<p>He collected the oil and cooled down the urine. After discarding the salts formed at the bottom of the mixture, he added back the red oil. By heating back the mixture for 16 hours, a white fume would come out, then oil, and finally <a href="https://www.sciencedirect.com/science/article/pii/S0045653511002499" title="A brief history of phosphorus: From the philosopher’s stone to nutrient recovery and reuse">phosphorus</a>.</p>
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<p>He was actually searching for the legendary <a href="https://www.sciencedirect.com/science/article/pii/S0045653511002499">Philosopher’s Stone</a> that would supposedly turn any metal into gold. He might have failed in that, but he showed how easy it was to isolate phosphorus from urine with unsophisticated tools.</p>
<h2>Reduce, reuse, recycle</h2>
<p>Today’s approaches to recycling of phosphorus from our wastes are way more practical and economical compared to Brandt’s method.</p>
<p>An increasing number of <a href="https://ostara.com/nutrient-management-solutions/">companies</a> are looking to <a href="https://www.suezwaterhandbook.com/degremont-R-technologies/sludge-treatment/recovery/recycle-phosphorus-from-effluent-to-produce-a-valuable-fertilizer-Phosphogreen">recover phosphorus</a> from waste water, including from <a href="https://www.sciencedirect.com/science/article/pii/S0043135410007025" title="Low-cost struvite production using source-separated urine in Nepal">urine</a>.</p>
<p>New <a href="http://www.vuna.ch/aurin/index_en.html">urine-derived fertilisers</a> have entered the market and the race is on to find the optimal technology to convert smelly urine into a safe, non-odorous commercial fertiliser. </p>
<p>In Australia, researchers from the University of Technology Sydney have developed a process that uses urine as a raw material to produce fertiliser and freshwater. Selected microorganisms are used to oxidise the (smelly) compounds in raw urine and convert volatile ammonia into more stable nitrates.</p>
<p>The treated urine is then filtered through a membrane, which retains the microorganisms allowing for their re-use, while allowing the soluble phosphorus and nitrogen to pass through. Treated and filtered urine is concentrated to reach nutrients concentration similar to commercial fertilisers. </p>
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<p>
<em>
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Read more:
<a href="https://theconversation.com/silver-makes-beautiful-bling-but-its-also-good-for-keeping-the-bacterial-bugs-away-115367">Silver makes beautiful bling but it's also good for keeping the bacterial bugs away</a>
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<p>At present, this fertiliser – named UrVal short for “You are Valuable” – is being tested at the Royal Botanical Garden in growing parsley.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/303056/original/file-20191122-112990-1ufdexv.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Parsley grown using UrVal fertiliser at the Sydney Royal Botanical Garden.</span>
<span class="attribution"><span class="source">Dr. Ibrahim El Saliby</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Clearly, these new innovations in nutrients recovery from wastes allow us to reduce the dependence on a finite resource (phosphorus).</p>
<p>But they could also enable us to explore the possibility of one day producing food outside of planet Earth where we need fertiliser. Phosphate rocks may not be available in such places, but we’d have plenty of urine.</p><img src="https://counter.theconversation.com/content/117751/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Federico Volpin does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We need phosphorus for life, as well as for fertiliser to help plants grow, but raw supplies are limited.Federico Volpin, PhD Fellow, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1218272019-10-30T18:58:57Z2019-10-30T18:58:57ZHow we discovered a glowing galactic ghoul<figure><img src="https://images.theconversation.com/files/288232/original/file-20190815-136195-1un1h97.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Makani</span> <span class="attribution"><span class="source">Jim Geach, David Tree, Peter Richardson, Games and Visual Effects Research Lab, University of Hertfordshire</span></span></figcaption></figure><p>It’s a classic Halloween tale. A group of ghost hunters visit a grand old house that is rumoured to be haunted. But after thoroughly exploring, they leave disappointed: there are no ghosts to be seen. Only later, when looking through their photographs of the place do they notice the mysterious apparition on the stairs. It was there all the time.</p>
<p>In our new work, <a href="https://www.nature.com/articles/s41586-019-1686-1">published in Nature</a>, we were shocked to discover an apparition of galactic proportions when looking at a familiar galaxy. The finding has huge significance because it demonstrates how chemical elements mix on very large scales around galaxies.</p>
<p>Your body, the Earth, and all the material world around you is made of a class of particle called “<a href="http://astronomy.swin.edu.au/cosmos/B/Baryons">baryons</a>”. Baryonic matter is “normal” everyday matter, such as carbon. So we’re intimately connected to the stuff.</p>
<p>Imagine you could put all the baryons in the universe into a jar. Now pick one of those particles at random. Where do you think it would have come from? Another human? A planet? Another galaxy entirely? The answer is surprising to most: it’s likely that baryon would have come from the space <em>between</em> galaxies. Most of the normal matter in the universe isn’t contained within galaxies at all.</p>
<p>When the universe was just a few hundred thousand years old, baryonic matter and <a href="https://theconversation.com/from-machos-to-wimps-meet-the-top-five-candidates-for-dark-matter-51516">dark matter</a>, an invisible and unknown substance making up the majority of matter in the universe, were intermingled in a nearly uniform fog. This was rippled with small density fluctuations, and over time these were amplified by gravity which teased them into a network of filaments lacing through the universe. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/288230/original/file-20190815-136203-idcvj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288230/original/file-20190815-136203-idcvj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288230/original/file-20190815-136203-idcvj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288230/original/file-20190815-136203-idcvj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288230/original/file-20190815-136203-idcvj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288230/original/file-20190815-136203-idcvj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288230/original/file-20190815-136203-idcvj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A large-scale simulation of the distribution of gas in the universe. Galaxies form at the dense nodes of the cosmic web drive outflows of gas back into the circumgalactic medium.</span>
<span class="attribution"><span class="source">Jim Geach & Rob Crain</span></span>
</figcaption>
</figure>
<p>We call it <a href="https://theconversation.com/scientists-start-mapping-the-hidden-web-that-scaffolds-the-universe-124616">the cosmic web</a>. At the densest points of the web, galaxies formed. In those galaxies, about a few hundred million years after the Big Bang, hydrogen started to burn in stars and nuclear fusion forged heavy elements including carbon and oxygen. Other elements were formed in cataclysmic stellar explosions. And at the centres of the galaxies, <a href="http://astronomy.swin.edu.au/cosmos/S/Supermassive+Black+Hole">supermassive black holes</a> grew by accumulating baryons, releasing energy in the process. </p>
<p>The blaze of young stars, the explosions of supernovae and the intensity of black holes have an important effect: they drive flows of gas through and out of galaxies. We’ve known for a long time that this “feedback” is essential for regulating the growth of galaxies and for mixing the different chemical elements in regions between stars. Without such mixing, you wouldn’t exist. Some of the iron in your blood comes from supernovae and the carbon comes from the ash of long-dead stars. We are all what the baddies in Harry Potter may call cosmic “mudbloods”.</p>
<p>Some of the flows of gas driven by star formation and black hole growth can escape galaxies, emerging into the “circumgalactic medium” – or CGM. This is the interface between the interstellar medium (the stuff between stars) and the wider intergalactic medium (the stuff between galaxies). </p>
<p>These winds transport heavy elements formed in galaxies out into the CGM. Some of these elements will later “rain” back down, perhaps to be incorporated in new solar systems. Others will spend the rest of eternity exiled in intergalactic space. </p>
<p>Computer simulations show this process in beautiful detail. But while we can measure outflows around galaxies in the real universe, we have not directly observed them on very large scales, which stretch hundreds of thousands of light years around galaxies. Until now.</p>
<h2>A galactic ghost</h2>
<p>We have used an instrument called the <a href="https://www2.keck.hawaii.edu/inst/kcwi/">Keck Cosmic Web Imager </a> to observe a galaxy that is part of a sample of galaxies we have been studying for some time. The instrument, based in Hawaii, is no ordinary camera. It measures the <em>spectrum</em> of light collected by the telescope, dispersing the light into its different frequencies, or colours. This allows us to see much more than would otherwise be possible with a traditional imaging camera. </p>
<p>The galaxies were of interest us because they are known to be driving extremely fast outflows of gas, travelling at 1,000 kilometres per second or more. They are also extremely compact compared to most galaxies. We think that most of them formed from the collision of two galaxies that have now coalesced into one. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/288191/original/file-20190815-136217-1t8w86.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288191/original/file-20190815-136217-1t8w86.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=329&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288191/original/file-20190815-136217-1t8w86.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=329&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288191/original/file-20190815-136217-1t8w86.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=329&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288191/original/file-20190815-136217-1t8w86.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=413&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288191/original/file-20190815-136217-1t8w86.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=413&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288191/original/file-20190815-136217-1t8w86.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=413&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A volume rendering of the KCWI data, revealing the huge Makani nebula and fast outflow.</span>
<span class="attribution"><span class="source">Jim Geach, David Tree, Peter Richardson, Games and Visual Effects Research Lab, University of Hertfordshire</span></span>
</figcaption>
</figure>
<p>When we looked at the KCWI data for the first time, it made the hairs rise on the back of our necks. We expected to detect something, but what we saw really surprised us. Surrounding the galaxy was a huge cloud of glowing gas, resembling the shape of an hourglass nearly a third of a million light years across. This glowing nebula dwarfs the central galaxy, but without KCWI you wouldn’t know it was there. </p>
<p>There’s nothing paranormal going on here though. From the colour, or frequency, of the light, we know it is being emitted by oxygen ions. Our analysis shows that the nebula has formed as the result of two distinct gas outflows – winds – that have propagated from the central galaxy into the CGM. We call the nebula <em>Makani</em> – a Hawaiian word for wind – out of respect for the cultural significance of the mountain from which the observations were made.</p>
<p>In Makani we are seeing directly for the first time the mechanism by which the CGM is being heated and enriched. Our initial analysis shows that the properties of the outflow broadly agree with predictions from theory. We now have <em>the</em> ideal system to study the process, and can use this data to refine the models.</p>
<p>What’s needed now is more examples of objects like Makani. And like the investigators we are, our team is now on the hunt for other spectres lurking out there.</p><img src="https://counter.theconversation.com/content/121827/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Geach receives funding from the Royal Society and the Science and Technology Facilities Council</span></em></p>New research shows how chemical elements mix in the universe. Without this process, you wouldn’t be here.James Geach, Professor of Astrophysics and Royal Society University Research Fellow, University of HertfordshireLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1179062019-07-17T19:49:37Z2019-07-17T19:49:37ZWhen an artist looks at a chemical element, what do they see?<figure><img src="https://images.theconversation.com/files/283811/original/file-20190712-173342-ypail1.jpg?ixlib=rb-1.1.0&rect=231%2C28%2C2728%2C1498&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Artists Damon Kowarsky and Hyunju Kim produced a series of 51 artistic interpretations of elements from the Periodic Table.
</span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>Artistic depictions of several chemical elements feature in a new exhibition from today as part of Australia’s celebrations for the <a href="https://www.iypt2019.org/">International Year of the Periodic Table</a>.</p>
<p>They are the work of artists <a href="http://damon.tk/">Damon Kowarsky</a> and Hyunju Kim, who worked together since December 2018 on the renditions that will be on display at <a href="https://www.quantumvictoria.vic.edu.au/">Quantum Victoria</a>, a specialist science and mathematics centre in the northern suburbs of Melbourne.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/282978/original/file-20190708-51262-gc4990.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/282978/original/file-20190708-51262-gc4990.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/282978/original/file-20190708-51262-gc4990.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=418&fit=crop&dpr=1 600w, https://images.theconversation.com/files/282978/original/file-20190708-51262-gc4990.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=418&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/282978/original/file-20190708-51262-gc4990.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=418&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/282978/original/file-20190708-51262-gc4990.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=525&fit=crop&dpr=1 754w, https://images.theconversation.com/files/282978/original/file-20190708-51262-gc4990.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=525&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/282978/original/file-20190708-51262-gc4990.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=525&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Damon Kowarsky and Hyunju Kim.</span>
<span class="attribution"><span class="source">Photo credit Delilah Yu</span></span>
</figcaption>
</figure>
<p>The project followed a chance meeting between Damon and Soula Bennett, the director of Quantum Victoria. Soula believes Science, Technology, Engineering and Mathematics (STEM) naturally extend to incorporate art.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-periodic-table-from-its-classic-design-to-use-in-popular-culture-52822">The periodic table: from its classic design to use in popular culture</a>
</strong>
</em>
</p>
<hr>
<p>So Damon and Kim were commissioned to produce a series of 51 artistic interpretations illustrating elements of significance in the story of the birth of the universe from the Periodic Table.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/283665/original/file-20190711-173329-ibd8mi.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/283665/original/file-20190711-173329-ibd8mi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/283665/original/file-20190711-173329-ibd8mi.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/283665/original/file-20190711-173329-ibd8mi.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/283665/original/file-20190711-173329-ibd8mi.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/283665/original/file-20190711-173329-ibd8mi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/283665/original/file-20190711-173329-ibd8mi.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/283665/original/file-20190711-173329-ibd8mi.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mat Greentree and Damon Kowarsky installing some of the works at Quantum.</span>
<span class="attribution"><span class="source">Photo credit Hyunju Kim</span></span>
</figcaption>
</figure>
<p>While Kowarsky was responsible for creating the drawings of the panels, the colours are by Kim.</p>
<p>As scientists who work with many elements from a scientific point of view, we were curious as to how Kowarsky chose some of the representations he did, so we asked him to describe the artistic process for some of his favourite elements. </p>
<h2>Helium (<a href="http://www.rsc.org/periodic-table/element/2/helium">He</a>)</h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/279644/original/file-20190616-158958-13i914n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/279644/original/file-20190616-158958-13i914n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/279644/original/file-20190616-158958-13i914n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/279644/original/file-20190616-158958-13i914n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/279644/original/file-20190616-158958-13i914n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/279644/original/file-20190616-158958-13i914n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/279644/original/file-20190616-158958-13i914n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/279644/original/file-20190616-158958-13i914n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The helium (He) artwork.</span>
<span class="attribution"><span class="source">Damon Kowarsky and Hyunju Kim</span></span>
</figcaption>
</figure>
<p><strong>Popular view:</strong> Used for balloons and to make your voice sound funny as it’s lighter and less dense than air.</p>
<p><strong>Chemist’s view:</strong> An unreactive (noble) gas that is particularly useful in cooling applications – liquid helium at -269°C is used to keep magnets at a superconducting temperature. Element with the lowest boiling point.</p>
<p><strong>Artist’s view (Damon):</strong> Helium is colourless, odourless, tasteless, almost completely inert, not commonly found on Earth, and named after the Sun, whose image dominated the design I completed for hydrogen.</p>
<p>Not a promising start in terms of visualisation! </p>
<p>In many ways it’s the most abstract of elements, and this ultimately was the clue that unlocked the design. The background composition is structured around a chart showing the passage of the Sun through the sky at the latitude and longitude of <a href="https://www.charleslatrobecollege.vic.edu.au/">Charles La Trobe College</a> (in Melbourne, the site of the installation) on January 1.</p>
<p>Overlaid onto this is the sequence of helium formation in stellar nucleosynthesis, a graph showing the rates of production and consumption of helium (despite its prevalence in the universe it’s a finite resource on Earth) and the bars of the absorption spectrum that allowed this, the first ever extraterrestrial element, to be discovered.</p>
<h2>Iron (<a href="http://www.rsc.org/periodic-table/element/26/iron">Fe</a>)</h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/279645/original/file-20190616-158925-1n32ffh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/279645/original/file-20190616-158925-1n32ffh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/279645/original/file-20190616-158925-1n32ffh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/279645/original/file-20190616-158925-1n32ffh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/279645/original/file-20190616-158925-1n32ffh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/279645/original/file-20190616-158925-1n32ffh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/279645/original/file-20190616-158925-1n32ffh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/279645/original/file-20190616-158925-1n32ffh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The iron (Fe) artwork.</span>
<span class="attribution"><span class="source">Damon Kowarsky and Hyunju Kim</span></span>
</figcaption>
</figure>
<p><strong>Popular view:</strong> Used to make steel. Iron ore is the source of much of Australia’s wealth. Found in blood.</p>
<p><strong>Chemist’s view:</strong> The most common element on Earth, making up around 35% of the its mass. Iron is used to catalyse a very important chemical reaction, the combination of nitrogen and hydrogen into ammonia, an essential component of fertiliser. </p>
<p><strong>Artist’s view:</strong> Iron is a pivotal element in the Periodic Table in terms of how the elements are created.</p>
<p>Showing a cross section of Earth allowed me to talk about its prevalence, maintain design coherence through the repetition of circles, and introduce bold and saturated colours. The smaller circle represents a red blood cell (iron is found in haemoglobin) and the pie charts show the relative distribution of iron isotopes.</p>
<p>In the bottom left corner the alchemical symbol for iron (Mars, the masculine attribute) breaks into the form of Earth. Alchemy is important as one of the foundations of modern chemistry and its symbols are historically and visually interesting. I didn’t want it to dominate though, so using a negative shape seemed a good way to balance all these concerns.</p>
<h2>Copper (<a href="http://www.rsc.org/periodic-table/element/29/copper">Cu</a>)</h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/279646/original/file-20190616-158917-1n030ed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/279646/original/file-20190616-158917-1n030ed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/279646/original/file-20190616-158917-1n030ed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/279646/original/file-20190616-158917-1n030ed.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/279646/original/file-20190616-158917-1n030ed.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/279646/original/file-20190616-158917-1n030ed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/279646/original/file-20190616-158917-1n030ed.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/279646/original/file-20190616-158917-1n030ed.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The copper (Cu) artwork.</span>
<span class="attribution"><span class="source">Damon Kowarsky and Hyunju Kim</span></span>
</figcaption>
</figure>
<p><strong>Popular view:</strong> For the older generation, copper pipes and <a href="https://www.ramint.gov.au/one-cent">1</a> and <a href="https://www.ramint.gov.au/two-cents">2</a> cent coins.</p>
<p><strong>Chemist’s view:</strong> Metal with very high thermal and electrical conductivity. Very useful for catalysing some chemical reactions, especially a so-called click reaction where two molecules can be quickly linked together under mild conditions.</p>
<p><strong>Artist’s view:</strong> With copper there’s the amazing colour and its history as one of the oldest metals known to humans.</p>
<p>I relied on the element’s utility and familiarity, and wanted to step away from symmetry and the geometric prevalence of circles. Even though copper is inorganic, its malleability and ductility lends an almost lifelike quality to its forms.</p>
<p>A map of Cyprus (copper is named for the place it was first discovered and mined) contributes to the overall balanced asymmetry of the design.</p>
<h2>Calcium (<a href="http://www.rsc.org/periodic-table/element/20/calcium">Ca</a>)</h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/279648/original/file-20190616-158936-k0xh3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/279648/original/file-20190616-158936-k0xh3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/279648/original/file-20190616-158936-k0xh3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/279648/original/file-20190616-158936-k0xh3i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/279648/original/file-20190616-158936-k0xh3i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/279648/original/file-20190616-158936-k0xh3i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/279648/original/file-20190616-158936-k0xh3i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/279648/original/file-20190616-158936-k0xh3i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The calcium (Ca) artwork.</span>
<span class="attribution"><span class="source">Damon Kowarsky and Hyunju Kim</span></span>
</figcaption>
</figure>
<p><strong>Popular view:</strong> Found in limestone, chalk and coral, and bones and teeth. </p>
<p><strong>Chemist’s view:</strong> Highly reactive and the most abundant metal in the human body. As calcium chloride, used as a desiccant to remove water from air and solvents so reactions can be done anhydrously (without the presence of water, which can interfere with some reactions).</p>
<p><strong>Artist’s view:</strong> Calcium is common in bones, shells and teeth. The challenge was finding images that were visually interesting and fitted the hexagonal shape.</p>
<p>Happily, this collection of human bones found on the web was neither articulated nor hopelessly jumbled. I was pleased how the curved bones (rib and collar) echo other design elements.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/283440/original/file-20190710-44441-10ytit5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/283440/original/file-20190710-44441-10ytit5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/283440/original/file-20190710-44441-10ytit5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/283440/original/file-20190710-44441-10ytit5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/283440/original/file-20190710-44441-10ytit5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/283440/original/file-20190710-44441-10ytit5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/283440/original/file-20190710-44441-10ytit5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The energy artwork.</span>
<span class="attribution"><span class="source">Damon Kowarsky and Hyunju Kim</span></span>
</figcaption>
</figure>
<p>Shells of course follow the Fibonacci Curve, whose elegant spiral can be seen in the another panel of the exhibit (“Energy”), where it represents a timeline of the universe.</p>
<h2>Nitrogen (<a href="http://www.rsc.org/periodic-table/element/7/nitrogen">N</a>)</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/279650/original/file-20190616-158953-9w19e6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/279650/original/file-20190616-158953-9w19e6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/279650/original/file-20190616-158953-9w19e6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/279650/original/file-20190616-158953-9w19e6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/279650/original/file-20190616-158953-9w19e6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/279650/original/file-20190616-158953-9w19e6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/279650/original/file-20190616-158953-9w19e6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The nitrogen (N) artwork.</span>
<span class="attribution"><span class="source">Damon Kowarsky and Hyunju Kim</span></span>
</figcaption>
</figure>
<p><strong>Popular view:</strong> Forms about 78% of Earth’s atmosphere, found in proteins and nucleic acids (DNA, RNA), and a key component of fertilisers.</p>
<p><strong>Chemist’s view:</strong> The triple bond (N≡N) form of nitrogen found in the atmosphere, is the second strongest bond in any diatomic molecule (composed of two elements). Although problematic for chemistry, it is useful as it releases large amounts of energy when broken. This is used both for fertilisers and explosives, and remains an essential process in the chemical industry.</p>
<p><strong>Artist’s view:</strong> Nitrogen compounds are essential for life. There are two main ways atmospheric nitrogen is converted to forms that are usable by plants and animals.</p>
<p>The first is lightning.</p>
<p>The second, and much less dramatic, is the symbiotic relationship between bacteria and the roots of certain plants. Typically these are beans and legumes but Australian wattles and acacias also contain nitrogen-fixing nodules. </p>
<h2>Other artistic elements</h2>
<p>Of course, Damon Kowarsky and Hyunju Kim are not the first to take an artistic look at the elements.</p>
<p>Other examples include a <a href="https://www.bowdoin.edu/news/2019/02/a-first-years-extraordinary-periodic-table.html">graphic artist’s version by Julie Hu</a> to convey to non-scientists the richness of what these substances bring to our world.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/silver-makes-beautiful-bling-but-its-also-good-for-keeping-the-bacterial-bugs-away-115367">Silver makes beautiful bling but it's also good for keeping the bacterial bugs away</a>
</strong>
</em>
</p>
<hr>
<p>Another is a <a href="https://www.sciencehistory.org/distillations/magazine/the-periodic-table-printmaking-project">periodic table printmaking project by Jennifer Schmitt</a>, the daughter of a chemistry teacher mother and an artistic father, she grew up seeing beauty in science.</p>
<p>There is also a <a href="http://www.instantshift.com/2015/09/02/periodic-table-elements-character-design/">depiction of the elements as characters by Kaycie Dunlap</a>, who was inspired by a desire make science more interesting by imagining what the elements would look like in our regular life.</p>
<p>Multiple quilting projects have drawn inspiration from sources such as the elements’ names, unique characteristics, and purposes (<a href="https://hyperallergic.com/236928/quirky-quilts-inspired-by-the-periodic-table/">curated by artist Jill Rumoshosky Werner in 2015</a>) or the wonderful stories about people, cultures, history, art, politics and science associated with them (<a href="https://periodictableinfabric.com/about-the-project/">curated by Kim Baird</a>).</p>
<hr>
<p><em>The artworks are on display from July 18, 2019, at Quantum Victoria, 235 Kingsbury Drive, Macleod, Victoria (they’re also <a href="http://art.damon.fastmail.net/project/science/periodictable/perindex.htm">available online</a>).</em></p>
<p><em>If you’d like to see them please call (03) 9223 1460 or email at <a href="mailto:admin@quantumvictoria.vic.edu.au">admin@quantumvictoria.vic.edu.au</a> to arrange a visit, as this is a school site (co-located with Charles La Trobe P-12 College).</em></p><img src="https://counter.theconversation.com/content/117906/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Blaskovich is a member of the Royal Australian Chemical Institute (RACI) and the American Chemical Society.</span></em></p><p class="fine-print"><em><span>Frances Separovic receives funding from Australian Research Council (ARC) and National Health & Medical Research Council (NHMRC). She is a member of the American Chemical Society, ANZMAG, Biophysical Society, ISMAR and RACI.</span></em></p>From heavy metal to lighter than air gas, these elements and others from the Periodic Table are transformed into artworks that go on display from today.Mark Blaskovich, Senior Research Officer, The University of QueenslandFrances Separovic AO FAA, Professor of Chemistry, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1105152019-04-02T13:21:14Z2019-04-02T13:21:14ZFrom medicine to nanotechnology: how gold quietly shapes our world<figure><img src="https://images.theconversation.com/files/266772/original/file-20190401-177163-1hbwmu2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">itti ratanakiranaworn/Shutterstock</span></span></figcaption></figure><p>The periodic table of chemical elements <a href="https://www.iypt2019.org/">turns 150</a> this year. The anniversary is a chance to shine a light on particular elements – some of which seem ubiquitous but which ordinary people beyond the world of chemistry probably don’t know much about.</p>
<p>One of these is gold, which was the subject of my postgraduate degrees in chemistry, and which I have <a href="https://www.researchgate.net/profile/Werner_Van_Zyl">been studying</a> for almost 30 years. In chemistry, gold can be considered a late starter when compared to most other metals. It was always considered to be chemically “inert” – but in recent decades it has flourished and a variety of interesting applications have emerged. </p>
<h2>A long, curious history</h2>
<p>Gold takes its name from the Latin word aurum (“yellow”). It’s an element with a long but rather mysterious history. For instance, it’s one of 12 confirmed elements on the periodic table whose discoverer <a href="http://www.rsc.org/periodic-table/element/79/gold">is unknown</a>. The others are carbon, sulfur, copper, silver, iron, tin, antimony, mercury, lead, zinc and bismuth.</p>
<p>Though we’re not sure who discovered it, there’s evidence to suggest it was known to the ancient Egyptians as far back as <a href="http://raregoldnuggets.com/?p=6724">3000 BC</a>. Historically, its primary use was for jewellery; this is still the case <a href="https://www.sbcgold.com/blog/top-6-common-uses-for-gold/">today</a>, it’s also used in mint coins. Gold is also found in ancient and modern art: it’s used to prepare ruby or purple pigment, or as gold leaf.</p>
<p>South Africa was once the top <a href="https://www.forbes.com/sites/greatspeculations/2018/06/13/top-10-gold-producing-countries/#7580dae84a87">gold-producing country</a> by far: it mined over 1,000 tonnes in 1970 alone. Its annual output has steadily fallen since then – the top three gold producing countries <a href="https://www.forbes.com/sites/greatspeculations/2018/06/13/top-10-gold-producing-countries/#7580dae84a87">in 2017</a> were China, Australia and Russia, with a <em>combined</em> output of almost 1000 tonnes. South Africa has dropped to 8th position, even surpassed by Peru and Indonesia. </p>
<p>But gold’s uses and its chemical properties extend into many other areas beyond jewels and minted coins. From pharmaceutical research to nanotechnology, this ancient element is being used to drive new technologies that are pushing the world into the future.</p>
<h2>Why and how it’s useful</h2>
<p>Of the 118 confirmed elements in the periodic table, nine are naturally occurring elements with radioactive <a href="http://www.world-nuclear.org/information-library/non-power-nuclear-applications/radioisotopes-research/radioisotopes-in-medicine.aspx">isotopes</a> that are used in so-called nuclear medicine. Gold is not radioactive, but is nevertheless very useful in medicine in the form of gold-containing drugs. </p>
<p>There are <a href="https://link.springer.com/article/10.1007/BF03214741">two classes</a> of gold drugs used to treat rheumatoid arthritis. One is injectable gold thiolates – molecules with a sulfur atom at one end, and a chemical chain of virtually any description attached to them – found in drugs such as Myocrisin, Solganol and Allocrysin. The other is an oral complex called <a href="https://www.drugbank.ca/drugs/DB00995">Auranofin</a>. </p>
<p>Gold is also increasingly being used in <a href="https://www.nature.com/collections/btvngkffdj">nanotechnology</a>. A nanomaterial is generally considered a material where any of its three dimensions is 100 nanometres (nm) or less. Nanotechnology is useful because it is not restricted to a particular material – any material could in principle be made into a nanomaterial – but rather a particular property: the property of size. </p>
<p>For example, gold in its bulk form has a distinct yellow colour. But as it is broken up into very small pieces it starts to change colour, through a range of red and purple, depending on the relative size of the gold nanoparticles. Such nanoparticles could be used in a variety of applications, for example in the <a href="https://www.sciencedirect.com/science/article/pii/S0039914018302054">biomedical</a> or <a href="https://www.azonano.com/article.aspx?ArticleID=3284">optical-electronic</a> fields. </p>
<p>Another exciting advancement for gold in nanotechnology was the discovery in 1983 that a clean gold surface dipped into a solution containing a thiolate could form <a href="https://pubs.rsc.org/en/content/articlepdf/2010/cs/b907301a">self-assembled monolayers</a>. These monolayers modify the surface of gold in very innovative ways. Research into surface modification is important because the surface of anything can show very different properties than the bulk (that is, the inside) of the same material. </p>
<h2>More to come</h2>
<p>Gold nanoparticles have also proven to be an effective catalyst. A catalyst is a material that increases the rate of a chemical reaction and so reduces the amount of energy required without itself undergoing any permanent chemical change. This is important because catalysis lies at the heart of many <a href="https://www.anl.gov/article/7-things-you-may-not-know-about-catalysis">manufactured goods</a> we use today. For example, a catalyst turns propylene into propylene oxide, which is the first step in making antifreeze. </p>
<p>Two discoveries in the 1980s made scientists look at gold catalysis differently. Masatake Haruta, in Osaka, Japan, made mixed oxides containing gold – and <a href="https://pubs.acs.org/doi/abs/10.1021/acscatal.5b01122">discovered</a> the material was remarkably active to catalyse the oxidation of toxic carbon monoxide into carbon dioxide. Today, this catalyst is found in vehicle exhausts.</p>
<p>At the same time <a href="https://www.cardiff.ac.uk/people/view/38519-hutchings-graham">Graham Hutchings</a>, who was working in industry in Johannesburg, South Africa, <a href="https://www.nature.com/articles/nchem.388">discovered a gold catalyst</a> that would work best for acetylene hydrochlorination. This process is central to PVC plastic, which is used in virtually all plumbing production. Until then, the industrial catalyst for this process was using environmentally unfriendly mercuric chloride material. </p>
<h2>Many applications</h2>
<p>In my opinion, gold has many more uses that haven’t yet been discovered. There is much more to come in the world of <a href="https://pubs.acs.org/doi/10.1021/ed400782p">gold research</a>. </p>
<p>There will, in the next few years, be new developments in how the element is used in, amongst others, medicine, nanotechnology and catalysis. It will also find new applications in relativistic quantum chemistry (combining relativistic mechanics with quantum chemistry), surface science (the physics and chemistry of surfaces and how they interact), luminescence and <a href="https://onlinelibrary.wiley.com/doi/10.1002/9783527626724.ch5">photophysics</a> – and more.</p><img src="https://counter.theconversation.com/content/110515/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Werner van Zyl does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Gold is one of 12 confirmed elements on the periodic table whose discoverer is unknown.Werner van Zyl, Associate Professor of Chemistry, Lecturer in sustainable biomass, energy and water systems, University of KwaZulu-NatalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1141952019-03-28T18:09:26Z2019-03-28T18:09:26ZFrom the bronze age to food cans, here’s how tin changed humanity<figure><img src="https://images.theconversation.com/files/266240/original/file-20190328-139341-e5mo6b.jpg?ixlib=rb-1.1.0&rect=0%2C475%2C4288%2C2355&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Tin comes from the ore cassiterite.</span> <span class="attribution"><span class="source">Shutterstock/PYP </span></span></figcaption></figure><p><em>To mark the <a href="https://www.iypt2019.org/">International Year of the Periodic Table of Chemical Elements</a> we’re taking a look at how researchers study some of the elements in their work.</em></p>
<p><em>Today’s it’s tin, a chemical that has little use by itself, but mix it with other elements and it takes on a whole new life.</em></p>
<hr>
<p>Mention tin and most people would think of the typical tin can, used to preserve foods you store in your cupboards. Tin is used here to help protect the can against corrosion (although <a href="https://www.ucan-packaging.com/blog/what-are-tin-cans-made-of/">not all cans</a> today contain tin).</p>
<p>But while the use of tin in canning only <a href="http://www.cancentral.com/content/nicolas-appert-father-canning">dates back to the early 1800s</a>, the mixing of tin with other elements dates back many centuries.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/266239/original/file-20190328-139374-v9hxsy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266239/original/file-20190328-139374-v9hxsy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266239/original/file-20190328-139374-v9hxsy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=393&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266239/original/file-20190328-139374-v9hxsy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=393&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266239/original/file-20190328-139374-v9hxsy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=393&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266239/original/file-20190328-139374-v9hxsy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=493&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266239/original/file-20190328-139374-v9hxsy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=493&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266239/original/file-20190328-139374-v9hxsy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=493&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The tin in cans helps to protect them from corrosion.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/tsausawest/8508069576/">Flickr/Salvation Army USA West</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Tin – <a href="http://www.rsc.org/periodic-table/element/50/tin">chemical symbol Sn</a> with an atomic number 50 on the periodic table – is soft and silvery in colour, with a melting point of only 232°C. At first sight it doesn’t seem to be a promising prospect for making anything. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/where-did-you-grow-up-how-strontium-in-your-teeth-can-help-answer-that-question-112705">Where did you grow up? How strontium in your teeth can help answer that question</a>
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<p>Somehow, humans discovered that adding controlled amounts of tin to copper produced a splendid, golden-yellow alloy we call bronze.</p>
<p>I first became interested in bronze during my final year undergraduate research project in 1978. That interest continues today – I’m working with colleagues in Thailand to reverse-engineer the technologies used to make ancient Thai bronze bangles. </p>
<h2>Early bronze</h2>
<p>The first known tin bronzes seem to have appeared in the Caucasus region of Eurasia in about 5800 to 4600 BCE. That these very scarce early examples of tin bronze may have been accidentally made from rather rare ores that naturally contained both copper and tin simultaneously.</p>
<p>There is abundant evidence that by about 3000 BCE, tin bronzes were being made in the Aegean and Middle East (Turkey, Syria, Iraq, Iran) by deliberately alloying tin and copper, with the ores being obtained from separate sources.</p>
<p>Clearly, a series of somewhat unlikely events had to occur before this could be the norm.</p>
<p>An accidental melt would have to have been made from suitable minerals containing oxides of tin and copper. The resulting metal would have to be recognised to have desirable properties, such as hardness, colour and toughness, such that superior weapons or ornaments could be produced.</p>
<p>Craftspeople would then have had to be organised enough to be able to work out how to repeat this smelting process to create artefacts such as swords, axe heads, bowls and bangles.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/266262/original/file-20190328-139374-1o61wq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266262/original/file-20190328-139374-1o61wq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266262/original/file-20190328-139374-1o61wq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=392&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266262/original/file-20190328-139374-1o61wq4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=392&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266262/original/file-20190328-139374-1o61wq4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=392&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266262/original/file-20190328-139374-1o61wq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=492&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266262/original/file-20190328-139374-1o61wq4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=492&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266262/original/file-20190328-139374-1o61wq4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=492&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This 4000-year-old bronze axe with a low tin content was found in Sweden.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/historiska/4655950292/">Flickr/The Swedish History Museum</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Trading networks then had to be established to bring the comparatively rare tin from faraway places, such as Afghanistan or Cornwall in Britain’s southwest, to any foundry. The metallurgical craft would have to be passed on to other practitioners, probably by oral means.</p>
<h2>The spread of bronze</h2>
<p>The trick of deliberately adding tin to copper then spread throughout the Old World, reaching Western Europe by about 2800 BCE, Egypt by 2200 BCE, the populous North China Plain by 2200 BCE, China’s Yunnan province by about 1400 BCE, Thailand by about 1100 BCE, and southern India by 1000 BC (if not a century or two earlier).</p>
<p>This has led to some robust discussion among archaeometallurgists on whether the special knowledge of tin’s useful attributes spread from a single founding location in the Middle East, or whether it had been repeatedly independently developed by indigenous craftspeople.</p>
<p>In the case of Thailand and Cambodia, arguments have been raised for several scenarios: that the technology was independently developed, that it was brought south from China (or maybe the reverse, exported from northeast Thailand to China), or that it was imported from Bengal.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/266247/original/file-20190328-139352-1e12w6u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266247/original/file-20190328-139352-1e12w6u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266247/original/file-20190328-139352-1e12w6u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=369&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266247/original/file-20190328-139352-1e12w6u.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=369&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266247/original/file-20190328-139352-1e12w6u.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=369&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266247/original/file-20190328-139352-1e12w6u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=464&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266247/original/file-20190328-139352-1e12w6u.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=464&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266247/original/file-20190328-139352-1e12w6u.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=464&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An ancient Thai bronze bangle from a site at Sa Kweo in east Thailand.</span>
<span class="attribution"><span class="source">Courtesy of Dr Supitcha Supansomboon and Assoc Prof Seriwat Saminpanya</span>, <span class="license">Author provided</span></span>
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<p>With China, some local scholars have favoured the view for independent local discovery of tin bronze, although it the balance of evidence suggests that the knowledge was transmitted by horseriding visitors from West Asia.</p>
<h2>African bronze</h2>
<p>Tin was also mined in precolonial times in Southern Africa, and some bronze artefacts – such as pieces of metal sheet or ingots – have been recovered at old metalworking sites there.</p>
<p>The available evidence for this region suggests the technology for producing and working iron, copper and bronze appeared contemporaneously at locations in sub-Saharan Africa, beginning about 500 BCE in the north and reaching South Africa in about 300 CE.</p>
<p>How did the metallurgical knowledge get to Southern Africa? Was it an indigenous discovery of the Bantu of East Africa that was then carried with them on their migrations, or was the skill transmitted southwards from the Middle East, and if so by who and how? </p>
<p>As in the case of Asia, interpretation of these issues can be coloured by modern political sensibilities. The question of the source of the metalworking skills that produced the beautiful copper and gold ornaments of the ancient city of Mapungubwe in South Africa, for example, has still not been settled. </p>
<h2>Bronze in the Americas</h2>
<p>The ancient cultures of the Americas also developed sophisticated skills for processing precious metals, copper and tin.</p>
<p>They were able to manufacture bronze artefacts such as rings, pendants, body ornaments, ornamental tweezers, sheet metal breastplates, large discs, ornamental shields and especially bells, by casting, albeit only from about 1000 CE in South America and then soon afterwards in western Mexico.</p>
<p>In the case of Mesoamerica, the knowledge of bronze was believed to have been carried north from Peru and Ecuador to Mexico by maritime traders. </p>
<p>Clearly, the ancient world, both Old and New, was well connected by lengthy trade routes along which ideas (and in many cases tin) flowed.</p>
<h2>The mix of tin</h2>
<p>The transmission of the technology can also be followed by paying attention to specific aspects of the physical metallurgy involved.</p>
<p>When more than about 15% tin by mass is added to the copper, the resulting alloy becomes rather brittle in its cast form, even if it still has a wonderfully warm golden yellow colour.</p>
<p>Somebody, somewhere, made the remarkable discovery that if such a casting is rapidly quenched from red heat into water (or better, brine), it becomes softer and relatively more ductile and workable.</p>
<p>The quenching heat treatment leaves a very characteristic needle-like microstructure (known as martensite) in the artefact that can be detected by a microscope. This tells an archaeologist that the part has been manufactured by a comparatively complex process, rather than merely cast.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/266257/original/file-20190328-139364-1tom8p2.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266257/original/file-20190328-139364-1tom8p2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266257/original/file-20190328-139364-1tom8p2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266257/original/file-20190328-139364-1tom8p2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266257/original/file-20190328-139364-1tom8p2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266257/original/file-20190328-139364-1tom8p2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266257/original/file-20190328-139364-1tom8p2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266257/original/file-20190328-139364-1tom8p2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The presence of martensite needles in microsections taken through high-tin bronze artefacts is a sure sign that they have been quenched into water from red heat.</span>
<span class="attribution"><span class="source">Michael Cortie</span>, <span class="license">Author provided</span></span>
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</figure>
<p>When the tin content is less than about 15%, no martensite forms and nothing remarkable happens on quenching.</p>
<p>The result obtained when heat-treating a high-tin bronze is counterintuitive because, when iron is treated this way, it becomes hard and brittle. The trick to make the bronze tough is so specific that it is most likely this knowledge was transmitted from person to person.</p>
<p>Its transfer across the Old World would have required knowledgeable individuals travelling significant distance to foreign climes. The appearance of these artefacts at far-flung locations across Eurasia and Africa is another sign of ancient globalisation.</p>
<h2>An extra element</h2>
<p>There is one more trick that appears in the ancient bronzes, although this one might have been independently discovered at more than one location.</p>
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Read more:
<a href="https://theconversation.com/hydrogen-fuels-rockets-but-what-about-power-for-daily-life-were-getting-closer-112958">Hydrogen fuels rockets, but what about power for daily life? We're getting closer</a>
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<p>Some time in the Late Bronze Age or Early Iron Age (around 500 BCE), craftspeople began to add lead to their tin bronze castings. This gives the molten metal extra fluidity, allowing it to flow into fine detail in a mould so that castings with fine details and embossed figures can be made.</p>
<p>As an element, lead is not as shiny or attractive as tin; it is much denser and is found in quite different ores such as galena (lead sulfide). The earliest known cast bronzes with significant controlled additions of lead appear to be from China (500 BCE to 200 CE). Once again, it was clearly a deliberate innovation, and once again it spread rapidly all over Eurasia.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/266271/original/file-20190328-139364-1gho715.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/266271/original/file-20190328-139364-1gho715.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266271/original/file-20190328-139364-1gho715.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=525&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266271/original/file-20190328-139364-1gho715.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=525&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266271/original/file-20190328-139364-1gho715.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=525&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266271/original/file-20190328-139364-1gho715.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=659&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266271/original/file-20190328-139364-1gho715.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=659&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266271/original/file-20190328-139364-1gho715.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=659&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Another ancient bronze from Thailand (measure is in centimetres).</span>
<span class="attribution"><span class="source">Courtesy of Dr Supitcha Supansomboon and Assoc Prof Seriwat Saminpanya</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>As more sites such as the ones in eastern Thailand are excavated, and as the database of alloy compositions and dates increases, it will become possible to cast more light on ancient routes of trade, migration and tech transfer. </p>
<p>The presence and usage of tin at these sites will act as a kind of metallurgical DNA, an indicator for ancient cultural and human exchanges.</p>
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<p><em>If you’re an academic researcher working with a particular element from the periodic table and have an interesting story to tell then why not <a href="https://theconversation.com/au/pitches">get in touch</a>.</em></p><img src="https://counter.theconversation.com/content/114195/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Cortie receives funding from the Australian Research Council.</span></em></p>On its own it’s just tin. But mix it with other elements and it turns into a material that helped shape the ancient world.Michael Cortie, Physics Discipline Leader, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1127052019-03-06T07:47:49Z2019-03-06T07:47:49ZWhere did you grow up? How strontium in your teeth can help answer that question<figure><img src="https://images.theconversation.com/files/262330/original/file-20190306-48423-zt3rdo.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Normanton Aboriginal rangers and archaeologists reburying the skeletal remains of Gkuthaarn and Kukatj children back on country.</span> <span class="attribution"><span class="source">Michael Westaway</span>, <span class="license">Author provided</span></span></figcaption></figure><p><em>To mark the <a href="https://www.iypt2019.org/">International Year of the Periodic Table of Chemical Elements</a> we’re taking a look at how researchers use some of the elements in their work.</em></p>
<p><em>Today’s it’s <a href="http://www.rsc.org/periodic-table/element/38/strontium">strontium</a>, a chemical that can help fireworks burn red. It’s also an element that is naturally found in teeth and can be used as way to identify where somebody grew up.</em></p>
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<p>Thousands of skeletal remains of Aboriginal people are kept in museums across Australia, North America and Europe.</p>
<p>Many Aboriginal people refer to these collections as ancestral remains. Although some have now been returned to their descendant communities, many more await return.</p>
<p>The challenge is knowing where to return them.</p>
<p>One estimate is that up to <a href="http://www.oxfordhandbooks.com/view/10.1093/oxfordhb/9780199569069.001.0001/oxfordhb-9780199569069-e-41">25%</a> of Aboriginal remains held in Australian institutions have no details of where they were taken from.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-teeth-can-tell-about-the-lives-and-environments-of-ancient-humans-and-neanderthals-104923">What teeth can tell about the lives and environments of ancient humans and Neanderthals</a>
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<p>Our study, published today in the journal <a href="https://doi.org/10.1002/gea.21728" title="A strontium isoscape of north‐east Australia for human provenance and repatriation">GeoArchaeology</a>, aims to tackle the issue of repatriating such remains. </p>
<p>Our work uses the element strontium to determine specifically where somebody grew up. Strontium is an element in all rock and is transferred into body tissues.</p>
<h2>Chemical help with the past</h2>
<p><a href="http://www.rsc.org/periodic-table/element/38/strontium">Strontium</a>, named after Strontian, a small town in western Scotland, is described as a soft, silvery metal that burns in air and reacts with water.</p>
<p>For decades the ratio of two forms of strontium (the isotopes ⁸⁷Sr/⁸⁶Sr) have been measured in archaeological and palaeontological material. These have helped in answering questions that relate to the behaviour of <a href="https://doi.org/10.1016/0883-2927(94)90063-9">past populations</a>. </p>
<p>Perhaps the most famous study involved the 5,000-year-old <a href="http://www.iceman.it/en/the-iceman/">ice man Otzi</a> who was found in the European Alps. <a href="https://www.sciencedirect.com/science/article/pii/S0168583X03004919">Strontium isotopes in Otzi’s teeth</a> helped scientists determine where he was born in northern Italy, which added to our understanding of the mobility of ancient European populations during the <a href="https://study.com/academy/lesson/copper-age-history.html">Chalcolithic period – the Copper Age from about 3500BCE to 2300BCE</a>. </p>
<p>Here in Australia, the strontium technique has had <a href="https://www.nma.gov.au/__data/assets/pdf_file/0006/4695/FriendsMar04-unraveling.pdf">some use in a few cases</a>, but in general is underutilised. </p>
<h2>More than DNA</h2>
<p>In a complementary project focusing on DNA, <a href="http://advances.sciencemag.org/content/4/12/eaau5064">research has shown</a> that genetic material can be used to help locate Aboriginal populations.</p>
<p>But the recovery of ancient DNA from many ancestral remains in Australia continues to prove challenging. Australia’s harsh environmental conditions lead to a poor state of preservation in many remains. This makes the recovery of biological material for DNA analyses difficult and in some cases not at all possible. </p>
<p>Using the isotope chemistry of tooth enamel and bone we can bypass these issues of preservation. The strontium-based process involves measuring a robust geochemical signature, not a biological one subject to decomposition. </p>
<p>Tooth enamel is the hardest substance in the human body and can hold evidence of the region where a person lived as a child. This makes it a suitable material to establish where a person was originally from. Bones are also useful as they help provide information about the burial site.</p>
<p>We use strontium isotopes to help with resolving the issue of provenance: the place where people belong. </p>
<h2>The abundance of isotopes</h2>
<p>The element strontium (chemical symbol, Sr) has an atomic number of 38 and four forms known as isotopes, ⁸⁴Sr, ⁸⁶Sr, ⁸⁷Sr and ⁸⁸Sr. Although these isotopes are stable, their natural abundance changes.</p>
<p>In particular, the amount of ⁸⁶Sr and ⁸⁷Sr in rock varies depending on the age of the rock and when it formed.</p>
<p>But strontium doesn’t just stay in rocks. When rocks break down, these isotopes end up in soil and water, where they are taken up by plants, animals and humans. </p>
<p>So for people it’s not simply a case of “you are <em>what</em> you eat”, but also “you are <em>where</em> you ate”. Our bodies become an isotope record of where we have been and what we have eaten. </p>
<p>One Elder from the advisory committee set up for this project, Gudjugudju, put it succinctly when he said that our ancestors carry the signature of their country in their bones and their teeth.</p>
<h2>A new look at Far North Queensland</h2>
<p>Before strontium isotopes in human teeth can be used to determine their place of origin we must first know how the element in the landscape changes. </p>
<p>We sampled strontium isotopes throughout Cape York to build a series of maps that can show where people may have grown up. These maps were developed and created in close consultation with an <a href="https://theconversation.com/poor-health-in-aboriginal-children-after-european-colonisation-revealed-in-their-skeletal-remains-106616">Aboriginal advisory committee representing several Cape York Aboriginal communities</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/261806/original/file-20190304-110123-1s8tkkt.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/261806/original/file-20190304-110123-1s8tkkt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/261806/original/file-20190304-110123-1s8tkkt.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=730&fit=crop&dpr=1 600w, https://images.theconversation.com/files/261806/original/file-20190304-110123-1s8tkkt.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=730&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/261806/original/file-20190304-110123-1s8tkkt.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=730&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/261806/original/file-20190304-110123-1s8tkkt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=917&fit=crop&dpr=1 754w, https://images.theconversation.com/files/261806/original/file-20190304-110123-1s8tkkt.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=917&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/261806/original/file-20190304-110123-1s8tkkt.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=917&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">One of many new maps: Cape York strontium isotope results can be used to match human values to environmental signals in soil, plants and water.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1002/gea.21728">Shaun Adams et al. 2019</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our results demonstrate that Australia’s ancient and diverse geology culminates in a wider range in strontium isotopes than found <a href="https://www.sciencedirect.com/science/article/pii/S0883292717304134">in overseas studies</a>.</p>
<p>We also found that strontium isotope signatures were transferred relatively unaltered from the geology through the hydrology and finally biology, ie. from the land to water, animals and humans. </p>
<p>For Cape York, we now have a partially complete <a href="https://theconversation.com/dna-from-ancient-aboriginal-australian-remains-enables-their-return-to-country-108168">genomic map</a> and a comprehensive isotopic map that Aboriginal groups can use as a tool to help determine the provenance of their ancestors. </p>
<h2>… but there’s a catch</h2>
<p>The Queensland Museum holds a large number of ancestral remains whose place of origin is still unknown. But current museum policy does not allow for invasive testing on ancestral remains without community consent. </p>
<p>This presents something of a “Catch 22”.</p>
<p>Aboriginal committees in other parts of the country have been thinking about how to return remains where there is no information on where they came from.</p>
<p>The <a href="https://www.aboriginalheritagecouncil.vic.gov.au/">Victorian Aboriginal Heritage Council</a>, which is the peak Aboriginal advisory committee for Victoria, has developed a policy, <a href="https://www.aboriginalheritagecouncil.vic.gov.au/report-ancestral-remains">Bringing the Ancestors Home</a>, that identifies the need to develop an approach to more seamlessly see the repatriation of ancestral remains to descendant communities.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/poor-health-in-aboriginal-children-after-european-colonisation-revealed-in-their-skeletal-remains-106616">Poor health in Aboriginal children after European colonisation revealed in their skeletal remains</a>
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<p>The Commonwealth National Advisory Committee for Indigenous Repatriation has developed a concept for a <a href="https://www.theguardian.com/australia-news/postcolonial-blog/2018/mar/04/pressure-builds-for-a-national-keeping-place-for-indigenous-remains">National Resting Place</a> in Canberra for ancestral remains whose descendant communities can’t be identified.</p>
<p>Our research in Far North Queensland, combining isotopes and ancient DNA, provides a new way to help these communities repatriate their ancestors.</p>
<p>A collaboration between science and Aboriginal communities may represent the best way forward for resolving this complex social issue.</p>
<hr>
<p><em>If you’re an academic researcher working with a particular element from the periodic table and have an interesting story to tell then why not <a href="https://theconversation.com/au/pitches">get in touch</a>.</em></p><img src="https://counter.theconversation.com/content/112705/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shaun Adams receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Michael Westaway is an ARC Future Fellow and receives funding from the Australian Research Council. </span></em></p>How do you return Aboriginal remains to their place of origin when you have no record of where they came from? Look to a chemical element that’s laid down in teeth as people grow up.Shaun Adams, Isotope Bioarchaeologist Research Fellow, Griffith UniversityMichael Westaway, Future Fellow, Australian Research Centre for Human Evolution, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1097652019-02-06T11:41:59Z2019-02-06T11:41:59ZThe politics of the periodic table – who gets the credit and why<figure><img src="https://images.theconversation.com/files/256881/original/file-20190201-127151-v79x6o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Random arrangement of the elements.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/periodical-chemical-elements-on-dark-blue-250330033?src=L6jraCI7K6wCz27iBZ58fw-1-16">arleksey/Shutterstock.com</a></span></figcaption></figure><p><a href="https://iupac.org/what-we-do/periodic-table-of-elements/">The periodic table</a> merges scientific inquiry, international politics, hero worship, desires for structure and desires for credit. </p>
<p>Formally, the modern periodic table is a systematic arrangement of the known chemical elements. The table is organized in an orderly way that shows the periodic occurrence of elements with similar chemical properties. Elements with similar chemical properties are stacked one on top of another in columns; going down each column from one row to the next the atoms of the elements get larger and heavier. Such periodic variations in the properties of elements are what Dmitri Mendeleev (1834-1907) and other scientists observed and sought to <a href="https://catalog.hathitrust.org/Record/001034519">summarize in tabular and other forms</a>. </p>
<p>Yet, the periodic table is not as objective as that basic description may sound. And who deserves credit for its creation is also not straightforward. <a href="https://chemistry.richmond.edu/faculty/kdonald/">I am a theoretical chemist</a>; I apply chemical principles and mathematics to answer questions and solve problems in various areas of chemistry. I’m also fascinated by the history of science and how we assign credit and name things in science. Those interests coupled with my chemistry background have led me over the years to intersections of the political and the scientific in the emergence of the modern periodic table. </p>
<p>There are, for instance, nationalistic tilts to the periodic table. Two elements (francium and gallium) are named for France and one each for Japan (nihonium), Germany (germanium) and Poland (polonium). Scandinavia got scandium; the elements berkelium, darmstadtium and moscovium give three cities each a spot on the table. One Swedish village – Ytterby – has claimed four elements: erbium, terbium, ytterbium and yttrium. <a href="http://doi.org/10.1021/ed066p731">A number of other places and people</a> have also <a href="https://www.newscientist.com/article/dn22317-competing-claims-pile-up-around-new-element-113/">snagged their little rectangles</a> on the table too, and that, in some cases, <a href="http://doi.org/10.1007/s10698-007-9042-1">only after serious disputes</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/257112/original/file-20190204-193217-1u3iq7n.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/257112/original/file-20190204-193217-1u3iq7n.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/257112/original/file-20190204-193217-1u3iq7n.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=318&fit=crop&dpr=1 600w, https://images.theconversation.com/files/257112/original/file-20190204-193217-1u3iq7n.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=318&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/257112/original/file-20190204-193217-1u3iq7n.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=318&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/257112/original/file-20190204-193217-1u3iq7n.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=399&fit=crop&dpr=1 754w, https://images.theconversation.com/files/257112/original/file-20190204-193217-1u3iq7n.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=399&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/257112/original/file-20190204-193217-1u3iq7n.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=399&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Periodic Table of the Elements.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/2/2e/Simple_Periodic_Table_Chart-en.svg">Wikimedia Commons</a></span>
</figcaption>
</figure>
<h2>Exalting Mendeleev</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/256879/original/file-20190201-108351-15koiu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/256879/original/file-20190201-108351-15koiu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=649&fit=crop&dpr=1 600w, https://images.theconversation.com/files/256879/original/file-20190201-108351-15koiu7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=649&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/256879/original/file-20190201-108351-15koiu7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=649&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/256879/original/file-20190201-108351-15koiu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=816&fit=crop&dpr=1 754w, https://images.theconversation.com/files/256879/original/file-20190201-108351-15koiu7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=816&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/256879/original/file-20190201-108351-15koiu7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=816&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Dmitri Ivanovich Mendeleev is often described as the sole creator of the periodic table.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/c/c8/DIMendeleevCab.jpg">Wikipedia</a></span>
</figcaption>
</figure>
<p>Among the elements named after people is element number 101, mendelevium (Md), which honors Mendeleev. Resisting other self-serving instincts, a group of <a href="http://pubs.acs.org/cen/80th/mendelevium.html">Berkeley scientists who discovered the radioactive Md</a> in 1955 decided to honor the Russian scientist Mendeleev for his contributions to formulating the periodic table. With the Cold War underway, however, they had to convince the Eisenhower administration to allow them to give up a spot on the table to a deceased Russian. </p>
<p>Why Mendeleev, though? Did he discover the periodic table? Hardly. </p>
<p>Mendeleev published in 1869 a paper that <a href="https://web.lemoyne.edu/giunta/EA/MENDELEEVann.HTML">organized then-known elements</a> in an authoritative, logical and systematic way, and he boldly predicted new ones. That paper was followed by others in the early 1870s that improved on the first and demonstrated the value of a <a href="https://www.scientificamerican.com/article/the-evolution-of-the-periodic-system/#googDisableSync">deep appreciation for the periodicity in chemistry</a>.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/256880/original/file-20190201-108338-16bdn8o.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/256880/original/file-20190201-108338-16bdn8o.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/256880/original/file-20190201-108338-16bdn8o.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=326&fit=crop&dpr=1 600w, https://images.theconversation.com/files/256880/original/file-20190201-108338-16bdn8o.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=326&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/256880/original/file-20190201-108338-16bdn8o.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=326&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/256880/original/file-20190201-108338-16bdn8o.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=409&fit=crop&dpr=1 754w, https://images.theconversation.com/files/256880/original/file-20190201-108338-16bdn8o.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=409&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/256880/original/file-20190201-108338-16bdn8o.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=409&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Periodic table by Mendeleev, 1871.</span>
</figcaption>
</figure>
<p>He, his papers and his table garnered a lot of attention and accelerated progress in our collective understanding of the elements and their relationships to each other. But the inspiration and the data that spurred Mendeleev’s achievements were owed in huge ways to predecessors and contemporaries such as <a href="https://www.britannica.com/biography/Amedeo-Avogadro">Amedeo Avogadro</a> (1776-1856), <a href="https://www.britannica.com/biography/Johann-Wolfgang-Dobereiner">Johann Wolfgang Döbereiner</a> (1780-1849) and <a href="https://www.britannica.com/biography/Stanislao-Cannizzaro">Stanislao Cannizzaro</a> (1826-1910). </p>
<h2>Contenders</h2>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/256885/original/file-20190201-108338-1dr6l1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/256885/original/file-20190201-108338-1dr6l1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/256885/original/file-20190201-108338-1dr6l1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=915&fit=crop&dpr=1 600w, https://images.theconversation.com/files/256885/original/file-20190201-108338-1dr6l1i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=915&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/256885/original/file-20190201-108338-1dr6l1i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=915&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/256885/original/file-20190201-108338-1dr6l1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1150&fit=crop&dpr=1 754w, https://images.theconversation.com/files/256885/original/file-20190201-108338-1dr6l1i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1150&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/256885/original/file-20190201-108338-1dr6l1i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1150&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Stanislao Cannizzaro.</span>
</figcaption>
</figure>
<p>At the end of a chemical congress in Karlsruhe, Germany, in September 1860, for instance, a decisive paper by Cannizzaro on the <a href="http://doi.org/10.1021/ed038p83">weights of the atoms of the elements</a> was <a href="https://doi.org/10.1098/rsnr.1966.0006">distributed to the attendees</a>. Mendeleev was at that meeting, and Cannizzaro’s work helped him to organize his 1869 table of 63 known elements, which he arranged according to observed chemical properties and assigned atomic weights. </p>
<p><a href="https://www.chemteam.info/Chem-History/Cannizzaro.html">Cannizzaro’s work was so convincing</a> that <a href="https://archive.org/details/bub_gb_UKwFAAAAIAAJ/page/n59">another attendee of the Karlsruhe meeting, J. Lothar Meyer</a>, reported that it felt to him as if <a href="https://doi.org/10.1021/ed027p365">the scales fell from his eyes</a> as he gained a new understanding of the elements. </p>
<p>Mendeleev’s periodic chart appeared some nine years after the Karlsruhe meeting (1869), but by 1868 <a href="https://www.britannica.com/biography/Alexandre-Emile-Beguyer-de-Chancourtois">Alexandre-Émile de Chancourtois</a> (1820-1886), <a href="https://en.wikipedia.org/wiki/William_Odling">William Odling</a> (1829-1921), <a href="https://www.britannica.com/biography/John-Newlands">John Newlands</a> (1837-1898) and <a href="https://en.wikipedia.org/wiki/Gustavus_Detlef_Hinrichs">Gustavus Hinrichs</a> (1836-1923), for example, had already served up, however technically inferior, credible <a href="https://doi.org/10.1098/rsta.2014.0172">attempts at periodic assemblies of the elements</a>. Newlands had also predicted the existence of other elements. </p>
<p>Meyer, enlightened as he was by Cannizzaro, devised tables in the 1860s before Mendeleev’s appeared. But his grand paper describing his table, which was similar to Mendeleev’s in many respects, was published in 1870, some months after <a href="http://doi.org/10.1021/ed046p136">Mendeleev’s 1869 paper</a>. Predictably, a <a href="http://doi.org/10.1021/ed046p136">slowly festering dispute</a> over priority eventually erupted between them. </p>
<h2>The impressive imperfect</h2>
<p>Does Mendeleev deserves credit for producing a superb table for his time, for advancing an understanding of how the properties of atoms are rhythmically linked, for underlining the power of that understanding and for brave predictions that pushed chemistry forward? Indeed. But great victories can have more than one hero, and the emergence of our periodic table is one such victory. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/257058/original/file-20190204-193217-181vpr0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/257058/original/file-20190204-193217-181vpr0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=894&fit=crop&dpr=1 600w, https://images.theconversation.com/files/257058/original/file-20190204-193217-181vpr0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=894&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/257058/original/file-20190204-193217-181vpr0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=894&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/257058/original/file-20190204-193217-181vpr0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1124&fit=crop&dpr=1 754w, https://images.theconversation.com/files/257058/original/file-20190204-193217-181vpr0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1124&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/257058/original/file-20190204-193217-181vpr0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1124&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">J. Lothar Meyer also contributed to the development of the periodic table.</span>
</figcaption>
</figure>
<p>Mendeleev’s work was neither the beginning nor the end of the charting of periodicity in chemistry. He <a href="https://doi.org/10.1098/rsta.2014.0172">misplaced some elements</a>, and his table was incomplete, even with his predictions: the group of so-called noble gases, for example, was discovered in the 1890s and was not anticipated in his papers. And general chemistry students today can readily spot other deficiencies in his 1869 table, too, based on our contemporary understanding of the nature of the elements. </p>
<p>In brief, Mendeleev’s contribution was tremendously impressive but was also imperfect, and the value of Meyer’s contributions was already sufficiently clear as to move the Royal Society of London to award both him and Mendeleev their prestigious <a href="https://royalsociety.org/grants-schemes-awards/awards/davy-medal/">Davy Medal</a> in 1892 “for their discovery of the periodic relations of the atomic weights.” Indeed, the joint award has been cited as evidence that what was seen by some to be <a href="https://doi.org/10.1016/S0039-3681(01)00023-1">especially valuable about Mendeleev’s table</a> was how it accommodated (as Meyer’s also did) the elements that were known, and not so much for Mendeleev’s predictions of new elements.</p>
<p>Was the Royal Society hoping too, through the joint award, to muffle the disquiet about priority or credit for the increasingly indispensable table? Perhaps. But if that were the intention, they failed. In science as in politics, the temptation to be simple rather than accurate can be quite strong. Scientists still say, “Mendeleev discovered the periodic table.”</p>
<h2>Noble intentions, political interventions</h2>
<p>Whatever one thinks of Meyer’s versus Mendeleev’s role in the incarnation of the table, history has not treated Meyer as well as it could have. One might ask, for example, if <a href="https://www.britannica.com/biography/Alfred-Nobel">Alfred Nobel</a> (1833-1896), who was a contemporary of Mendeleev and <a href="https://www.britannica.com/search?query=lothar+meyer">Meyer</a> (1830-1895) but who aided in no direct way our understanding of periodicity, is more deserving than Meyer or <a href="https://www.britannica.com/biography/John-Newlands">Newlands</a> or <a href="https://www.britannica.com/biography/Alexandre-Emile-Beguyer-de-Chancourtois">de Chancourtois</a> of a spot on the period table. </p>
<p>In my opinion, the answer is clearly no.</p>
<p>Even so, element 102 – nobellium – was named after Alfred Nobel, partly because he died rich enough to fund his bequest to the world of the Nobel Prizes. But there are ironies here. Nobel got a spot on their periodic table, but neither Mendeleev, Meyer, nor anyone else received a Nobel Prize for demonstrating periodicity or developing the periodic table. </p>
<p>Mendeleev was actually in <a href="https://www.nobelprize.org/nomination/redirector/?redir=archive/">nine Nobel Prize nominations</a> between 1905 and 1907, but he never won. Some claim he was denied because Swedish scientist <a href="https://www.britannica.com/biography/Svante-Arrhenius">Svante Arrhenius</a> held substantial animosity toward him. Mendeleev harshly criticized a theory (unrelated to periodicity, about how salts dissolve in water) that <a href="http://doi.org/10.1021/bk-2017-1262.ch003">Arrhenius had proposed</a>, and – although Arrhenius was not a member of the award committee – he was famous, influential and highly regarded by his peers on the Nobel Prize selection committees. But that and other <a href="https://doi.org/10.1096/fj.13-238758">Nobel Prize backstories</a> are separate political discussions. </p>
<p>Politics, hero worship and jockeying for credit are often closer than desirable to scientific practice. A place where they all converge is on that great list of the chemical elements known so far to humanity. </p>
<p>Who has won the priority dispute? <a href="http://rruff.info/uploads/Lotharmeyerite.pdf">A class of minerals</a> has been named after Meyer, but if having a private room on the periodic table is the gold standard for its fathers, then Mendelevium has answered the question.</p>
<p>The United Nations, scientists and science-loving people everywhere celebrate the periodic table this year for the marvelous chemical good that it has offered and continues to offer us. And we acknowledge as well its storied past, internal political warts and all.</p><img src="https://counter.theconversation.com/content/109765/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kelling Donald receives funding from The National Science Foundation, and the Dreyfus Foundation. </span></em></p>2019 is the International Year of the Periodic Table. The person who typically gets credit for its creation is Dimitri Mendeleev. But there were many more chemists who should be recognized.Kelling Donald, Associate Professor of Chemistry, University of RichmondLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1103772019-01-24T14:12:13Z2019-01-24T14:12:13ZPeriodic table: new version warns of elements that are endangered<figure><img src="https://images.theconversation.com/files/255121/original/file-20190123-135136-oxtm6j.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Period pains. </span> <span class="attribution"><span class="source">European Chemical Society</span></span></figcaption></figure><p>It is amazing to think that everything around us is made up from just 90 building blocks – the naturally occurring chemical elements. <a href="https://eic.rsc.org/feature/mendeleev-the-man-and-his-legacy-/2020190.article">Dmitri Mendeleev</a> put the 63 of these known at the time into order and published his first version of what we now recognise as the periodic table in 1869. In that year, the American civil war was just over, Germany was about to be unified, Tolstoy published War and Peace, and the Suez Canal was opened.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/255154/original/file-20190123-135157-1gqalek.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/255154/original/file-20190123-135157-1gqalek.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/255154/original/file-20190123-135157-1gqalek.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=656&fit=crop&dpr=1 600w, https://images.theconversation.com/files/255154/original/file-20190123-135157-1gqalek.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=656&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/255154/original/file-20190123-135157-1gqalek.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=656&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/255154/original/file-20190123-135157-1gqalek.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=825&fit=crop&dpr=1 754w, https://images.theconversation.com/files/255154/original/file-20190123-135157-1gqalek.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=825&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/255154/original/file-20190123-135157-1gqalek.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=825&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dmitri the daddy.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/red-fireworks-135339725?src=vlkaAD5YFpgZI_sxK6waGg-1-48">Marusya Chaika</a></span>
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<p>There are now 118 known elements but only 90 that occur in nature. The rest are mostly <a href="https://www.theguardian.com/environment/2019/jan/23/uk-has-biggest-fossil-fuel-subsidies-in-the-eu-finds-commission">super-heavy substances</a> that have been created in laboratories in recent decades through nuclear reactions, and rapidly decay into one or more of the natural elements. </p>
<p>Where each of these natural elements sits in the periodic table allows us to know immediately a great deal about how it will behave. To commemorate the 150th anniversary of this amazing resource, UNESCO <a href="https://www.iypt2019.org">has proclaimed</a> 2019 as the International Year of the Periodic Table. </p>
<p>As part of the celebrations, the European Chemical Society has published a completely new version of the periodic table – see main image. It is designed to give an eye-catching message about sustainable development; based on an <a href="http://chemreflux.blogspot.com/2014/12/periodic-table-with-wildly-inaccurate.html">original idea</a> in the 1970s from the American chemist William Sheehan, the table has been completely redrawn so that the area occupied by each element represents its abundance on a log scale. </p>
<h2>Red for danger</h2>
<p>Each area of the new table has been colour coded to indicate its vulnerability. In most cases, elements are not lost but, as we use them, they become dissipated and much less easy to recover. Red indicates that dissipation will make the elements much less readily available in 100 years or less – that’s helium (He), silver (Ag), tellurium (Te), gallium (Ga), germanium (Ge), strontium (Sr), yttrium (Y), zinc (Zn), indium (In), arsenic (As), hafnium (Hf) and tantalum (Ta).</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/well-all-be-worse-off-when-the-helium-balloon-pops-14124">We'll all be worse off when the helium balloon pops</a>
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</em>
</p>
<hr>
<p>To give just a couple of examples, helium is used to cool the magnets in MRI scanners and to dilute oxygen for deep sea diving. Vital rods in nuclear reactors use hafnium. Strontium salts are added to fireworks and flares to produce vivid red colours. Yttrium is a component of camera lenses to make them shock and heat resistant. It is also used in lasers and alloys. Gallium, meanwhile, is used to make very high-quality mirrors, light-emitting diodes and solar cells. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/255153/original/file-20190123-135163-1ykgksz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/255153/original/file-20190123-135163-1ykgksz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/255153/original/file-20190123-135163-1ykgksz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/255153/original/file-20190123-135163-1ykgksz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/255153/original/file-20190123-135163-1ykgksz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/255153/original/file-20190123-135163-1ykgksz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/255153/original/file-20190123-135163-1ykgksz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/255153/original/file-20190123-135163-1ykgksz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">From strontium with love.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/red-fireworks-135339725?src=vlkaAD5YFpgZI_sxK6waGg-1-48">Gary L Jones</a></span>
</figcaption>
</figure>
<p>Meanwhile, the orange and yellow areas on the new periodic table anticipate problems caused by increased use of these elements, too. Green means that plenty is available – including the likes of oxygen (O), hydrogen (H), aluminium (Al) and calcium (Ca). </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-periodic-table-is-150-but-it-could-have-looked-very-different-106899">The periodic table is 150 – but it could have looked very different</a>
</strong>
</em>
</p>
<hr>
<p>Four elements – tin (Sn), tantalum (Ta) tungsten (W) and gold (Au) – are coloured in black because they often come from conflict minerals; that is, from mines where wars are fought over their ownership. They can all be more ethically sourced, so it’s intended as a reminder that manufacturers must carefully trace their origin to be sure that people did not die in order to provide the minerals in question. </p>
<h2>Smartphone shortages</h2>
<p>Out of the 90 elements, 31 carry a smartphone symbol – reflecting the fact that they are all contained in these devices. This includes all four of the elements from conflict minerals and another six with projected useful lifetimes of less than 100 years. </p>
<p>Let us consider indium (In), for instance, which is coloured red on the table. Every touch screen contains a transparent conducting layer of indium tin oxide. There is quite a lot of indium, but it is already highly dispersed. It is a byproduct of zinc manufacture, but there is only enough from that source <a href="https://www.nrel.gov/docs/fy16osti/62409.pdf">for about</a> 20 years. Then the price will start to rise quickly – unless we do something to preserve current stocks. </p>
<p>The three main possibilities are: replace, recycle or use less. Huge efforts are being made to find alternative materials based on Earth-abundant elements. Reclaiming indium from used screens is possible and being attempted. But when we look at the Periodic Table and the very precious nature of so many of the elements, can we possibly justify changing our phone every two or so years? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/255156/original/file-20190123-135160-5anpoz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/255156/original/file-20190123-135160-5anpoz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/255156/original/file-20190123-135160-5anpoz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/255156/original/file-20190123-135160-5anpoz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/255156/original/file-20190123-135160-5anpoz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/255156/original/file-20190123-135160-5anpoz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/255156/original/file-20190123-135160-5anpoz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/255156/original/file-20190123-135160-5anpoz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The wrong call.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/realistic-modern-touch-smartphone-red-color-1046186929?src=zvk4G9RovTqg6uDQwro6dw-1-57">full vector</a></span>
</figcaption>
</figure>
<p>At present over 1m phones <a href="https://www.theguardian.com/news/2002/sep/25/mobilephones.uknews">are traded</a> in every month in the UK alone (10m in Europe, 12m <a href="https://www.businessgreen.com/bg/sponsored/2235847/mobile-phone-recycling-good-for-you-and-the-environment">in the US</a>). When we trade in our smartphones, many of them go to the developing world initially for reuse. Most end up in landfill sites or attempts are made to extract a few of the elements <a href="https://www.engadget.com/2018/02/06/ethical-smartphone-conscious-consumption/">under appalling conditions</a>. The other elements remain in acidic brews. This, and the very many that lie around in drawers, is how the elements in mobile phones become dissipated. </p>
<p>The number of phones we trade in could be greatly reduced and with it the demand on limited resources such as indium. In this context, the recent <a href="https://theconversation.com/what-is-really-eating-apple-and-why-steve-jobs-would-not-be-doing-a-lot-better-109377">Apple profit warning</a>, partly due to customers replacing their iPhones slightly less frequently, was at least a sign of improvement. </p>
<p>But as the new version of the periodic table underlines, we must do all we can to conserve and recycle the 90 precious building blocks that make up our wonderfully diverse world. If we don’t start taking these problems more seriously, many of the objects and technologies that we now take for granted may be relics of a more abundant age a few generations from now – or available only to richer people.</p><img src="https://counter.theconversation.com/content/110377/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Cole-Hamilton is affiliated with the UK Liberal Democratic Party. He is Vice-President of the European Chemical Society (EuChemS). He is Past-President of the Royal Society of Chemistry Dalton Division covering Inorganic Chemistry. He is a member of the Royal Society of Edinburgh (RSE) Education Committee, RSE Learned Societies Group on STEM Education, RSE European Strategy Group and chairs the sub-group on Research, Innovation and Tertiary Education. He is a Trustee of the Wilkinson Charitable Foundation.</span></em></p>Exactly 150 years after Mendeleev’s classic formulation, it’s time for one for the resource-hungry 21st century.David Cole-Hamilton, Emeritus Professor of Chemistry, University of St AndrewsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1068992019-01-02T09:12:42Z2019-01-02T09:12:42ZThe periodic table is 150 – but it could have looked very different<figure><img src="https://images.theconversation.com/files/249935/original/file-20181211-76968-1lsh5rp.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Theodor Benfey's spira table (1964).</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/Category:Alternative_forms_of_periodic_table#/media/File:Elementspiral_(polyatomic).svg">DePiep/Wikipedia</a></span></figcaption></figure><p>The <a href="https://theconversation.com/the-periodic-table-from-its-classic-design-to-use-in-popular-culture-52822">periodic table </a> stares down from the walls of just about every chemistry lab. The credit for its creation generally goes to <a href="http://www.rsc.org/education/teachers/resources/periodictable/pre16/develop/mendeleev.htm">Dimitri Mendeleev</a>, a Russian chemist who in 1869 wrote out the known elements (of which there were 63 at the time) on cards and then arranged them in columns and rows according to their chemical and physical properties. To celebrate the 150th anniversary of this pivotal moment in science, the UN has proclaimed 2019 to be the <a href="https://iupac.org/united-nations-proclaims-international-year-periodic-table-chemical-elements/">International year of the Periodic Table</a>.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/249435/original/file-20181207-128205-1xfg95r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249435/original/file-20181207-128205-1xfg95r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/249435/original/file-20181207-128205-1xfg95r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=786&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249435/original/file-20181207-128205-1xfg95r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=786&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249435/original/file-20181207-128205-1xfg95r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=786&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249435/original/file-20181207-128205-1xfg95r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=988&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249435/original/file-20181207-128205-1xfg95r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=988&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249435/original/file-20181207-128205-1xfg95r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=988&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">John Dalton’s element list.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Dalton%27s_Element_List.jpg">Wikimedia Commons</a></span>
</figcaption>
</figure>
<p>But the periodic table didn’t actually start with Mendeleev. Many had tinkered with arranging the elements. Decades before, chemist John Dalton tried to <a href="http://www.sussexvt.k12.de.us/science/the%20history%20of%20the%20world%201500-1899/john%20dalton%27s%20periodic%20tables.htm">create a table</a> as well as some rather interesting symbols for the elements (they didn’t catch on). And just a few years before Mendeleev sat down with his deck of homemade cards, <a href="https://www.britannica.com/biography/John-Newlands">John Newlands</a> also created a table sorting the elements by their properties.</p>
<p>Mendeleev’s genius was in what he left out of his table. He recognised that certain elements were missing, yet to be discovered. So where Dalton, Newlands and others had laid out what was known, Mendeleev left space for the unknown. Even more amazingly, he accurately predicted the properties of the missing elements.</p>
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<a href="https://images.theconversation.com/files/249713/original/file-20181210-76959-1jny1g2.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249713/original/file-20181210-76959-1jny1g2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249713/original/file-20181210-76959-1jny1g2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=350&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249713/original/file-20181210-76959-1jny1g2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=350&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249713/original/file-20181210-76959-1jny1g2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=350&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249713/original/file-20181210-76959-1jny1g2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=440&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249713/original/file-20181210-76959-1jny1g2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=440&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249713/original/file-20181210-76959-1jny1g2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=440&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dimitry Mendeleev’s table complete with missing elements.</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
</figcaption>
</figure>
<p>Notice the question marks in his table above? For example, next to Al (aluminium) there’s space for an unknown metal. Mendeleev foretold it would have an atomic mass of 68, a density of six grams per cubic centimetre and a very low melting point. Six years later <a href="https://www.lindahall.org/paul-emile-lecoq-de-boisbaudran/">Paul Émile Lecoq de Boisbaudran,</a> isolated <a href="http://www.rsc.org/periodic-table/element/31/gallium">gallium</a> and sure enough it slotted right into the gap with an atomic mass of 69.7, a density of 5.9g/cm³ and a melting point so low that <a href="https://www.youtube.com/watch?v=N6ccRvKKwZQ">it becomes liquid in your hand</a>. Mendeleev did the same for <a href="https://www.meta-synthesis.com/webbook/35_pt/pt_database.php?PT_id=303">scandium, germanium</a> and <a href="http://www.rsc.org/periodic-table/element/43/technetium">technetium</a> (which wasn’t discovered until 1937, 30 years after his death).</p>
<p>At first glance Mendeleev’s table doesn’t look much like the one we are familiar with. For one thing, the modern table has a bunch of elements that Mendeleev overlooked (and failed to leave room for), most notably the noble gases (such as helium, neon, argon). And the table is oriented differently to our modern version, with elements we now place together in columns arranged in rows.</p>
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<a href="https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=318&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=318&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=318&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=400&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=400&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249442/original/file-20181207-128193-vpgzxa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=400&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Today’s periodic table.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/File:Simple_Periodic_Table_Chart-en.svg">Offnfopt/Wikipedia</a></span>
</figcaption>
</figure>
<p>But once you give Mendeleev’s table a 90-degree turn, the similarity to the modern version becomes apparent. For example, the halogens – fluorine (F), chlorine (Cl), bromine (Br), and Iodine (I) (the J symbol in Mendeleev’s table) – all appear next to one another. Today they are arranged in the table’s 17th column (or group 17 as chemists prefer to call it).</p>
<h2>Period of experimentation</h2>
<p>It may seem a small leap from this to the familiar diagram but, years after Mendeleev’s publications, there was plenty of experimentation with alternative layouts for the elements. Even before the table got its permanent right-angle flip, folks suggested some weird and wonderful twists.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249444/original/file-20181207-128187-1dgwvl6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249444/original/file-20181207-128187-1dgwvl6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249444/original/file-20181207-128187-1dgwvl6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=630&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249444/original/file-20181207-128187-1dgwvl6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=630&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249444/original/file-20181207-128187-1dgwvl6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=630&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249444/original/file-20181207-128187-1dgwvl6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=791&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249444/original/file-20181207-128187-1dgwvl6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=791&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249444/original/file-20181207-128187-1dgwvl6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=791&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Heinrich Baumhauer’s spiral.</span>
<span class="attribution"><span class="source">Reprinted (adapted) with permission from Types of graphic classifications of the elements. III. Spiral, helical, and miscellaneous charts, G. N. Quam, Mary Battell Quam. Copyright (1934) American Chemical Society.</span></span>
</figcaption>
</figure>
<p>One particularly striking example is Heinrich <a href="https://www.meta-synthesis.com/webbook/35_pt/JCE_PTs_1934.pdf">Baumhauer’s spiral</a>, published in 1870, with hydrogen at its centre and elements with increasing atomic mass spiralling outwards. The elements that fall on each of the wheel’s spokes share common properties just as those in a column (group) do so in today’s table. There was also Henry Basset’s <a href="http://www.chem.msu.ru/eng/misc/mendeleev/hyper/">rather odd “dumb-bell”</a> formulation of 1892.</p>
<p>Nevertheless, by the beginning of the 20th century, the table had settled down into a familiar horizontal format with the <a href="https://www.meta-synthesis.com/webbook/35_pt/JCE_PTs_1934_medium.pdf">strikingly modern looking version from Alfred Werner</a> in 1905. For the first time, the noble gases appeared in their now familiar position on the far right of the table. Werner also tried to take a leaf out of Mendeleev’s book by leaving gaps, although he rather overdid the guess work with suggestions for elements lighter than hydrogen and another sitting between hydrogen and helium (none of which exist).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249445/original/file-20181207-128196-1g58xp9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249445/original/file-20181207-128196-1g58xp9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249445/original/file-20181207-128196-1g58xp9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=227&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249445/original/file-20181207-128196-1g58xp9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=227&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249445/original/file-20181207-128196-1g58xp9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=227&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249445/original/file-20181207-128196-1g58xp9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=285&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249445/original/file-20181207-128196-1g58xp9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=285&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249445/original/file-20181207-128196-1g58xp9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=285&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Alfred Werner’s modern incarnation.</span>
<span class="attribution"><span class="source">Reprinted (adapted) with permission from Types of graphic classifications of the elements. I. Introduction and short tables, G. N. Quam, Mary Battell Quam. Copyright (1934) American Chemical Society.</span></span>
</figcaption>
</figure>
<p>Despite this rather modern looking table, there was still a bit of rearranging to be done. Particularly influential was <a href="https://link.springer.com/article/10.1007/s10698-008-9062-5">Charles Janet’s</a> version. He took a physicist’s approach to the table and used a newly discovered <a href="https://theconversation.com/explainer-quantum-physics-570">quantum theory</a> to create a layout based on electron configurations. The resulting “<a href="https://www.sciencenews.org/blog/context/old-periodic-table-could-resolve-today%25E2%2580%2599s-element-placement-dispute">left step</a>” table is still preferred by many physicists. Interestingly, Janet also provided space for elements right up to number 120 despite only 92 being known at the time (we’re only at 118 now).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249448/original/file-20181207-128187-11i867s.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249448/original/file-20181207-128187-11i867s.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249448/original/file-20181207-128187-11i867s.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249448/original/file-20181207-128187-11i867s.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249448/original/file-20181207-128187-11i867s.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249448/original/file-20181207-128187-11i867s.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249448/original/file-20181207-128187-11i867s.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249448/original/file-20181207-128187-11i867s.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Charles Janet’s left-step table.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Charles_Janet">Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Settling on a design</h2>
<p>The modern table is actually <a href="https://www.meta-synthesis.com/webbook/documents/LEACH_Basic_Elemental_Property.pdf">a direct evolution of Janet’s version</a>. The alkali metals (the group topped by lithium) and the alkaline earth metals (topped by beryllium) got shifted from far right to the far left to create a very wide looking (long form) periodic table. The problem with this format is that it doesn’t fit nicely on a page or poster, so largely for aesthetic reasons the f-block elements are usually cut out and deposited below the main table. That’s how we arrived at the table we recognise today.</p>
<p>That’s not to say folks haven’t tinkered with layouts, often as an attempt to highlight correlations between elements that aren’t readily apparent in the conventional table. There are literally hundreds of variations (check out Mark Leach’s <a href="https://www.meta-synthesis.com/webbook/35_pt/pt_database.php">database</a>) with <a href="https://www.meta-synthesis.com/webbook/35_pt/pt_database.php?Button=Spiral+Formulations">spirals</a> and <a href="https://www.meta-synthesis.com/webbook/35_pt/pt_database.php?Button=3D+Formulations">3D versions</a> being particularly popular, not to mention more tongue-in-cheek variants.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/249485/original/file-20181207-128196-ie5nlv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249485/original/file-20181207-128196-ie5nlv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=476&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249485/original/file-20181207-128196-ie5nlv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=476&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249485/original/file-20181207-128196-ie5nlv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=476&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249485/original/file-20181207-128196-ie5nlv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=598&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249485/original/file-20181207-128196-ie5nlv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=598&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249485/original/file-20181207-128196-ie5nlv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=598&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">3D ‘Mendeleev flower’ version of the table.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/Category:Alternative_forms_of_periodic_table">Тимохова Ольга/Wikipedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>How about my <a href="https://universityofhull.app.box.com/v/elementstubemap">own fusion of two iconic graphics</a>, Mendeleev’s table and Henry Beck’s London Underground map below? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249481/original/file-20181207-128187-1stsxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249481/original/file-20181207-128187-1stsxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249481/original/file-20181207-128187-1stsxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249481/original/file-20181207-128187-1stsxv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249481/original/file-20181207-128187-1stsxv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249481/original/file-20181207-128187-1stsxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249481/original/file-20181207-128187-1stsxv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249481/original/file-20181207-128187-1stsxv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The author’s underground map of the elements.</span>
<span class="attribution"><span class="source">Mark Lorch</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Or the dizzy array of imitations that aim to give a science feel to categorising everything from <a href="http://ecx.images-amazon.com/images/I/81CFIrGYpzL._SL1500_.jpg">beer</a> to <a href="https://ohmy.disney.com/wp-content/uploads/sites/25/2015/03/omd_periodictableofdisney_final.jpg">Disney characters</a>, and my particular favourite “<a href="http://www.crispian.net/PTIR/Nonsense.html">irrational nonsense</a>”. All of which go to show how the periodic table of elements has become the iconic symbol of science.</p><img src="https://counter.theconversation.com/content/106899/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Lorch does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>There have been some rather wacky looking suggestions for arranging the chemical elements.Mark Lorch, Professor of Science Communication and Chemistry, University of HullLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/861772018-12-07T11:39:53Z2018-12-07T11:39:53ZHunting for rare isotopes: The mysterious radioactive atomic nuclei that will be in tomorrow’s technology<figure><img src="https://images.theconversation.com/files/249379/original/file-20181206-128202-1d16zby.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Researchers have identified 3,000 radioactive isotopes – and predict 4,000 more are out there.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/high-energy-particles-collision-abstract-illustration-539127385">GiroScience/Shutterstock.com</a></span></figcaption></figure><p>When you hear the term “radioactive” you likely think “bad news,” maybe along the lines of fallout from an atomic bomb.</p>
<p>But radioactive materials are actually used in a wide range of beneficial applications. In medicine, they routinely help diagnose and treat disease. Irradiation helps keep a number of foods free from insects and invasive pests. Archaeologists use them to figure out how old an artifact might be. And the list goes on.</p>
<p>So what is radioactivity?</p>
<p>It’s the spontaneous emission of radiation when an atom’s dense center – called its nucleus – transforms into a different one. Whether in the form of particles or electromagnetic waves called gamma rays, radiation transfers energy away from the atomic nucleus.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249353/original/file-20181206-128193-1ucj6s2.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249353/original/file-20181206-128193-1ucj6s2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249353/original/file-20181206-128193-1ucj6s2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=390&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249353/original/file-20181206-128193-1ucj6s2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=390&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249353/original/file-20181206-128193-1ucj6s2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=390&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249353/original/file-20181206-128193-1ucj6s2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=490&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249353/original/file-20181206-128193-1ucj6s2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=490&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249353/original/file-20181206-128193-1ucj6s2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=490&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The nuclear chart showing the 250 or so stable isotopes in pink, the around 3,000 known rare isotopes in green and the approximately 4,000 predicted isotopes in grey.</span>
<span class="attribution"><span class="source">Erin O'Donnell, Michigan State University</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Through experiments, nuclear physicists have seen about 3,000 different kinds of nuclei to date. Current theories, though, predict the existence of about 4,000 more that have never yet been observed. Around the world, thousands of scientists, <a href="https://www.artemisspyrou.com">including me</a>, continue to study these tiny constituents of matter, while governments spend billions of dollars on building powerful new machines that will produce more and more exotic nuclei – and maybe eventually more technologies that will further improve modern life. </p>
<h2>The birth of nuclear physics</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/249330/original/file-20181206-128193-1qr8qdq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249330/original/file-20181206-128193-1qr8qdq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/249330/original/file-20181206-128193-1qr8qdq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=714&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249330/original/file-20181206-128193-1qr8qdq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=714&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249330/original/file-20181206-128193-1qr8qdq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=714&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249330/original/file-20181206-128193-1qr8qdq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=898&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249330/original/file-20181206-128193-1qr8qdq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=898&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249330/original/file-20181206-128193-1qr8qdq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=898&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Henri Becquerel, 1904.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Becquerel,_Henri_(1852-1908).jpg">Library of Congress</a></span>
</figcaption>
</figure>
<p>French physicist <a href="https://www.nobelprize.org/prizes/physics/1903/becquerel/biographical/">Henri Becquerel</a> discovered natural radioactivity in 1896. He was trying to study how uranium salts phosphoresce – that is, emit light – when they’re exposed to sunlight. Becquerel placed a uranium sample on a photographic plate covered with opaque paper and left it in direct sunlight. The plate got foggy, which he concluded was due to sun exposure.</p>
<p>Thanks to a few days of cloudy weather, though, Becquerel left his whole setup in a dark drawer. Surprisingly, the photographic plate still fogged up, even in the absence of light. Sunlight had nothing to do with his previous observation. It was the natural radioactivity of the uranium samples that had this effect. As the uranium nuclei decayed – that is, transformed into different nuclei – they spontaneously emitted lightwaves that registered on the photographic plates.</p>
<p>Becquerel’s discovery ushered in a new era of physics and launched the field of nuclear science. For this work, he won the Nobel Prize in 1903.</p>
<p>Since then, nuclear scientists have unraveled a lot of the inner workings of the atomic nucleus, and have harnessed its amazing energy both for good and unfortunately not so good uses. Nuclear physics discoveries have given us ways to look inside our bodies noninvasively, ways to create energy without air pollution, and ways to study our history and our environment.</p>
<h2>On the atomic level</h2>
<p>The known atomic nuclei belong to 118 different elements, some of them naturally occurring and some of them human-made. For every element on the periodic table there are many different “isotopes,” from the Greek word “ισότοπο,” which means “same place,” implying the same place on the periodic table of the elements.</p>
<p>To be the same element, two isotopes must have the same number of protons – the positively charged subatomic particle. It’s their number of neutrons – subatomic particles with no charge at all – that can vary significantly.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249332/original/file-20181206-128196-1lo06wp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249332/original/file-20181206-128196-1lo06wp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249332/original/file-20181206-128196-1lo06wp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249332/original/file-20181206-128196-1lo06wp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249332/original/file-20181206-128196-1lo06wp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249332/original/file-20181206-128196-1lo06wp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249332/original/file-20181206-128196-1lo06wp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249332/original/file-20181206-128196-1lo06wp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The periodic table lists all the elements based on their number of protons. Isotopes of an element have the same number of protons – for Beryllium it’s four – but various numbers of neutrons.</span>
<span class="attribution"><span class="source">Artemis Spyrou</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>For example, gold is element 79 on the periodic table, and all isotopes of gold will have the same metallic, yellowish appearance. However, there are 40 known isotopes of gold that have been discovered, and another roughly 20 are theorized to exist. Only one of these isotopes is the “stable,” or naturally occurring, form of gold you might be wearing on your ring finger right now. The rest are radioactive isotopes, also known as “rare isotopes.”</p>
<p>Rare isotopes each have unique properties: They live for different amounts of time, from a fraction of a second to a few billion years, and they release different types of radiation and different amounts of energy.</p>
<p>For example, modern smoke detectors <a href="https://www3.epa.gov/radtown/americium-smoke-detectors.html">use the isotope Americium-241</a>, which emits a type of radiation called alpha particles that have a very short range. The radioactivity can’t travel more than a couple of inches in air. Americium-241 lives for a few hundred years.</p>
<p>On the other hand, the isotope Fluorine-18, which is commonly used in medical PET scans, lives for only about 100 minutes – long enough to complete the scan, but short enough to avoid irradiating the healthy body unnecessarily for an extended period. The secondary electromagnetic radiation that comes from Fluorine-18 is in the form of long-range gamma rays, which allows it to travel out of the body and into the PET cameras. </p>
<p>These different nuclear properties make each rare isotope unique, and nuclear physicists have to design specialized experiments to study each one of them separately.</p>
<h2>Hunting for more</h2>
<p>Current nuclear science research strives to develop new techniques for discovering new isotopes, understanding their properties, and eventually producing and harvesting them efficiently.</p>
<p>Producing rare isotopes <a href="https://www.youtube.com/watch?v=EPG919lJK8s&t=57s">is not an easy task</a>; it requires large machines that will make nuclei travel, and collide with each other, at speeds close to the speed of light. During these collisions nuclei can fuse together, or they can break each other apart, producing new nuclei, potentially with previously unseen combinations of protons and neutrons.</p>
<p>Nuclear physicists have dedicated equipment - detectors - that can observe these newly formed nuclei and the radiation they emit, and study their properties. For example, at the <a href="https://www.nscl.msu.edu">National Superconducting Cyclotron Laboratory</a> <a href="https://scholar.google.com/citations?user=MFjq3JsAAAAJ&hl=en&oi=ao">where I work</a>, my group has developed an extremely efficient gamma ray detector we called SuN.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/249321/original/file-20181206-128202-nxvd3q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249321/original/file-20181206-128202-nxvd3q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/249321/original/file-20181206-128202-nxvd3q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=561&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249321/original/file-20181206-128202-nxvd3q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=561&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249321/original/file-20181206-128202-nxvd3q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=561&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249321/original/file-20181206-128202-nxvd3q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=705&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249321/original/file-20181206-128202-nxvd3q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=705&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249321/original/file-20181206-128202-nxvd3q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=705&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The SuN detector at the National Superconducting Cyclotron Laboratory measures gamma rays and helps researchers study the properties of rare isotopes.</span>
<span class="attribution"><span class="source">Artemis Spyrou</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>The majority of the known isotopes emit gamma radiation when they decay. We want to know how much energy is released in this process, how many different gamma rays are emitted and how the energy is shared between them, and how long it takes for the decay to take place. SuN can answer these questions about whichever isotope we are investigating.</p>
<p>In a typical experiment, we implant a beam of rare isotopes at the center of SuN. The rare isotopes will decay of their own accord after a short amount of time, roughly one second or less, and emit their characteristic radiation. SuN detects these emitted gamma rays. It’s our job as nuclear experimentalists to put together the puzzle of how those gamma rays were emitted and what they tell us about the properties of the new isotope.</p>
<p>These kinds of production and detection techniques are complex and costly, and therefore there are only a handful of rare isotope laboratories in the world that can produce and study the most exotic nuclear species.</p>
<p>It’s impossible to predict which new discoveries in basic research will have an impact on people’s lives. Who could have known 100 years ago, when the electron was discovered, that for a few decades almost every house in the developed world would have an electron machine – otherwise known as a <a href="https://electronics.howstuffworks.com/tv3.htm">cathode-ray tube</a> – to watch television? And who could have guessed that the discovery of radioactivity would eventually lead to <a href="https://rps.nasa.gov/power-and-thermal-systems/power-systems/current/">space exploration powered by radioactive decays</a>?</p>
<p>In the same way, we cannot predict which rare isotope discoveries will be the game-changers, but with more than half of the predicted isotopes still unexplored, to me the possibilities feel endless.</p><img src="https://counter.theconversation.com/content/86177/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Artemis Spyrou receives funding from the National Science Foundation and the Department of Energy/National Nuclear Security Administration. </span></em></p>Alongside their famous dangers, radioactive materials have many beneficial uses. With as many more predicted as have already been discovered, nuclear physicists are searching for more isotopes.Artemis Spyrou, Associate Professor of Nuclear Physics, Michigan State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/841232017-11-06T06:10:41Z2017-11-06T06:10:41ZHeard of the element erbium? It could pave the way to a quantum internet<figure><img src="https://images.theconversation.com/files/193366/original/file-20171106-1017-to7lbe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A laser beam (yellow) causes a path of red fluorescence in a rare earth crystal. </span> <span class="attribution"><span class="source">Stuart Hay, ANU</span>, <span class="license">Author provided</span></span></figcaption></figure><p>If you were to try reciting the periodic table, you might stumble before you got to the rare earth elements. </p>
<p>Comprising yttrium (element 39) and everything from lanthanum (element 57) to lutetium (element 71), the rare earths are unfamiliar to most of us. But they are vital for technologies that we use every day, from fluorescent lights to the internet.</p>
<p>Recently, <a href="https://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys4254.html">we have shown</a> that one rare earth element, erbium (element 68), can play a crucial part in the future quantum internet.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-periodic-table-from-its-classic-design-to-use-in-popular-culture-52822">The periodic table: from its classic design to use in popular culture</a>
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</em>
</p>
<hr>
<h2>What are rare earths, anyway?</h2>
<p>Even the name “rare earths” is misleading. In fact, rare earth elements are not particularly rare. Cerium, for example, is as common as copper. </p>
<p>The name “rare earths” came about because they are dispersed in ores and are difficult to extract, so only small amounts could be isolated. Today, though, we extract over <a href="https://foreignpolicy.com/2016/07/12/decoder-rare-earth-market-tech-defense-clean-energy-china-trade/">100,000 tonnes</a> of rare earth elements annually.</p>
<p>The applications of the rare earth elements are wide ranging. Metal alloys – that is, mixtures – containing rare earth ions such as neodymium make the strongest magnets. They’re used in everything from audio speakers to electric motors. The catalytic converters that reduce harmful emissions in car exhausts use cerium, and rechargeable nickel metal hydride batteries use lanthanum.</p>
<p>Crystals containing rare earth ions absorb and emit light at a variety of useful wavelengths in the ultraviolet, visible and infrared ranges of the spectrum. </p>
<p>This means that rare earth elements are common in lighting. Crystal powders - known as phosphors - containing europium, terbium, and cerium are used to create the red, green, and blue pixels that make up a full-colour plasma television display. They’re also mixed together to create the white light from compact fluorescent light bulbs.</p>
<h2>Erbium and the internet</h2>
<p>Erbium, meanwhile, plays a vital role in the internet’s optical fibre network. </p>
<p>Most global internet traffic travels as light in optical fibres. This allows fast transmission with very low loss at the right wavelength (around 1,500-1,600 nanometres; one nanometre is one billionth of a metre). </p>
<p>Even so, over long distances this loss - light leaking out of the fibre - is a major problem, and the light has to be periodically amplified. </p>
<p>Since erbium absorbs and emits light at 1,550 nanometres, exactly in the middle of the fibre telecom band, it can be used to amplify the light in a device called an Erbium-Doped Fibre Amplifier (EDFA). </p>
<p>The undersea optical fibres that form the backbone of the internet have EDFAs <a href="https://www.osa-opn.org/home/articles/volume_25/march_2014/features/sea_change_the_challenges_facing_submarine_optical/">every 80km or so</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/193369/original/file-20171106-1061-1mcd7s1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/193369/original/file-20171106-1061-1mcd7s1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/193369/original/file-20171106-1061-1mcd7s1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/193369/original/file-20171106-1061-1mcd7s1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/193369/original/file-20171106-1061-1mcd7s1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/193369/original/file-20171106-1061-1mcd7s1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/193369/original/file-20171106-1061-1mcd7s1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Erbium-doped optical fiber, illuminated with green light.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/w/index.php?curid=23322774">Ximeg /wikimedia commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>The quantum internet</h2>
<p>The internet allows current-day computers to talk to each other, but researchers are now developing quantum computers. Erbium could play an important role here too.</p>
<p>Quantum computers make use of one of the stranger aspects of quantum physics - quantum superposition, where particles can simultaneously exist in two different states - to encode information. To get these computers talking to each other, we need a new type of network that can maintain this quantum information. In other words, a quantum internet. </p>
<p>To make the quantum internet we need to build the quantum analogues of each element in the classical internet. The quantum analogue of the EDFAs used as amplifiers in our current undersea optical fibres is called a quantum repeater. In turn, this would require quantum memory, which is used to store and synchronise information traffic in the network.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/from-flatscreen-tvs-to-your-smartphone-the-element-boron-deserves-more-attention-82374">From flatscreen TVs to your smartphone: the element boron deserves more attention</a>
</strong>
</em>
</p>
<hr>
<p>Researchers around the world have been working on quantum memories for over a decade, but storing quantum information for even 1/1,000 of a second is challenging. We need storage times of at least 1/10 second for the quantum internet. </p>
<p>It has also been very hard to make memories that work for light in the fibre telecom band, the wavelength required for optical fibres.</p>
<p>The best approach to date has been to build the memory at a different wavelength, and to try to interface it with the optical fibre band by, for example, converting the wavelength of the light at the input and output of the memory - a challenge in itself.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/193378/original/file-20171106-1068-wz6ctz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/193378/original/file-20171106-1068-wz6ctz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=394&fit=crop&dpr=1 600w, https://images.theconversation.com/files/193378/original/file-20171106-1068-wz6ctz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=394&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/193378/original/file-20171106-1068-wz6ctz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=394&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/193378/original/file-20171106-1068-wz6ctz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=496&fit=crop&dpr=1 754w, https://images.theconversation.com/files/193378/original/file-20171106-1068-wz6ctz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=496&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/193378/original/file-20171106-1068-wz6ctz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=496&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Crystals containing erbium, which gives them their pink colour.</span>
<span class="attribution"><span class="source">Milos Rancic, ANU</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Will erbium help?</h2>
<p>Since erbium interacts with light at exactly the right wavelength, it seems like the obvious choice for a quantum memory. However, erbium is poor at storing quantum information. </p>
<p>The problem is that erbium is sensitive to the tiny magnetic field fluctuations that occur in crystals, and this rapidly degrades any quantum information it holds. </p>
<p>Recently, <a href="https://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys4254.html">we found</a> that applying a large magnetic field can greatly improve the quantum storage time of certain erbium crystals. This field, which is similar to that inside a hospital MRI machine, quiets the magnetic field fluctuations. The erbium storage time can then improve by a factor of 10,000 to more than 1 second.</p>
<p>This is the first system compatible with the optical fibres required for a global quantum internet that has a storage time long enough for this network. The next steps are to build quantum repeaters with this system, and install them on a test network to measure their performance. </p>
<p>In the future, erbium materials may be as integral to the quantum internet as they already are to our current internet.</p><img src="https://counter.theconversation.com/content/84123/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rose Ahlefeldt receives funding from the Australian Research Council. </span></em></p>Rare earth elements aren’t actually that rare - but they certainly are useful. Erbium is used right now in the internet’s optical fibre network, and could one day be applied in quantum networks.Rose Ahlefeldt, Research Fellow, Laser Physics Centre, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/861042017-10-24T20:18:24Z2017-10-24T20:18:24ZCosmic alchemy: Colliding neutron stars show us how the universe creates gold<figure><img src="https://images.theconversation.com/files/191637/original/file-20171024-30571-frs0vu.jpg?ixlib=rb-1.1.0&rect=96%2C0%2C803%2C573&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Illustration of hot, dense, expanding cloud of debris stripped from the neutron stars just before they collided.</span> <span class="attribution"><a class="source" href="https://svs.gsfc.nasa.gov/12740">NASA's Goddard Space Flight Center/CI Lab</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>For thousands of years, humans have searched for a way to turn matter into gold. <a href="https://doi.org/10.1086/660139">Ancient alchemists</a> considered this precious metal to be the highest form of matter. As human knowledge advanced, the mystical aspects of alchemy gave way to the sciences we know today. And yet, with all our advances in science and technology, the origin story of gold remained unknown. Until now. </p>
<p>Finally, scientists know how the universe makes gold. Using our <a href="https://doi.org/10.3847/2041-8213/aa91c9">most advanced telescopes and detectors</a>, we’ve seen it created in the cosmic fire of the two colliding stars first detected by LIGO via the gravitational wave they emitted.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/191658/original/file-20171024-30605-ei0pxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/191658/original/file-20171024-30605-ei0pxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/191658/original/file-20171024-30605-ei0pxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/191658/original/file-20171024-30605-ei0pxa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/191658/original/file-20171024-30605-ei0pxa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/191658/original/file-20171024-30605-ei0pxa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/191658/original/file-20171024-30605-ei0pxa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/191658/original/file-20171024-30605-ei0pxa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The electromagnetic radiation captured from GW170817 now confirms that elements heavier than iron are synthesized in the aftermath of neutron star collisions.</span>
<span class="attribution"><a class="source" href="https://www.caltech.edu/news/caltech-led-teams-strike-cosmic-gold-80074">Jennifer Johnson/SDSS</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Origins of our elements</h2>
<p>Scientists have been able to piece together where many of the elements of the periodic table come from. The Big Bang <a href="https://doi.org/10.1146/annurev.nucl.56.080805.140437">created hydrogen</a>, the lightest and most abundant element. As stars shine, they fuse hydrogen into heavier elements like carbon and oxygen, the elements of life. In their dying years, stars create the common metals – aluminum and iron – and blast them out into space in different types of <a href="https://doi.org/10.1146/annurev.astro.38.1.191">supernova</a> <a href="https://doi.org/10.1146/annurev-astro-082708-101737">explosions</a>.</p>
<p>For decades, scientists have theorized that these stellar explosions also explained the origin of the heaviest and most rare elements, like gold. But they were missing a piece of the story. It hinges on the object left behind by the death of a massive star: a neutron star. Neutron stars pack one-and-a-half times the mass of the sun into a ball only 10 miles across. A teaspoon of material from their surface would weigh 10 million tons.</p>
<p>Many stars in the universe are in binary systems – two stars bound by gravity and orbiting around each other (think Luke’s home planet’s suns in “Star Wars”). A pair of massive stars might eventually end their lives as a pair of neutron stars. The neutron stars orbit each other for hundreds of millions of years. But Einstein says that their dance cannot last forever. Eventually, they must collide.</p>
<h2>Massive collision, detected multiple ways</h2>
<p>On the morning of August 17, 2017, a ripple in space passed through our planet. It was detected by the LIGO and Virgo gravitational wave detectors. This cosmic disturbance came from a pair of city-sized neutron stars colliding at one third the speed of light. The <a href="https://doi.org/10.1103/PhysRevLett.119.161101">energy of this collision</a> surpassed any atom-smashing laboratory on Earth.</p>
<p>Hearing about the collision, astronomers around the world, <a href="http://kilonova.org/about.html">including</a> <a href="https://dabrown.expressions.syr.edu/">us</a>, jumped into action. Telescopes large and small scanned the patch of sky where the gravitational waves came from. Twelve hours later, three telescopes caught sight of a brand new star – called a kilonova – in a galaxy called NGC 4993, about 130 million light years from Earth.</p>
<p>Astronomers had captured the light from the cosmic fire of the colliding neutron stars. It was time to point the world’s biggest and best telescopes toward the new star to see the visible and infrared light from the collision’s aftermath. In Chile, the Gemini telescope swerved its large 26-foot mirror to the kilonova. NASA steered the Hubble to the same location.</p>
<figure>
<img src="http://kilonova.org/img/DECam_fading_kn_final.gif">
<figcaption><span class="caption">Movie of the visible light from the kilonova fading away in the galaxy NGC 4993, 130 million light years away from Earth.</span></figcaption>
</figure>
<p>Just like the embers of an intense campfire grow cold and dim, the afterglow of this cosmic fire quickly faded away. Within days the visible light faded away, leaving behind a warm infrared glow, which eventually disappeared as well. </p>
<h2>Observing the universe forging gold</h2>
<p>But in this fading light was encoded the answer to the age-old question of how gold is made.</p>
<p>Shine sunlight through a prism and you will see our sun’s spectrum – the colors of the rainbow spread from short wavelength blue light to long wavelength red light. This spectrum contains the fingerprints of the elements bound up and forged in the sun. Each element is marked by a unique fingerprint of lines in the spectrum, reflecting the different atomic structure.</p>
<p>The spectrum of the kilonova contained the fingerprints of the heaviest elements in the universe. Its light carried the telltale signature of the neutron-star material decaying into platinum, gold and other so-called <a href="https://en.wikipedia.org/wiki/R-process">“r-process” elements</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/191689/original/file-20171024-30613-1iljobe.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/191689/original/file-20171024-30613-1iljobe.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/191689/original/file-20171024-30613-1iljobe.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/191689/original/file-20171024-30613-1iljobe.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/191689/original/file-20171024-30613-1iljobe.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/191689/original/file-20171024-30613-1iljobe.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/191689/original/file-20171024-30613-1iljobe.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/191689/original/file-20171024-30613-1iljobe.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Visible and infrared spectrum of the kilonova. The broad peaks and valleys in the spectrum are the fingerprints of heavy element creation.</span>
<span class="attribution"><span class="source">Matt Nicholl</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>For the first time, humans had seen alchemy in action, the universe turning matter into gold. And not just a small amount: This one collision created at least 10 Earths’ worth of gold. You might be wearing some gold or platinum jewelry right now. Take a look at it. That metal was created in the atomic fire of a neutron star collision in our own galaxy billions of years ago – a collision just like the one seen on August 17.</p>
<p>And what of the gold produced in this collision? It will be blown out into the cosmos and mixed with dust and gas from its host galaxy. Perhaps one day it will form part of a new planet whose inhabitants will embark on a millennia-long quest to understand its origin.</p><img src="https://counter.theconversation.com/content/86104/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Duncan Brown receives funding from the National Science Foundation and the Research Corporation for Science Advancement.</span></em></p><p class="fine-print"><em><span>Edo Berger receives funding from the National Science Foundation and NASA. </span></em></p>Until the recent observation of merging neutron stars, how the heaviest elements come to be was a mystery. But their fingerprints are all over this cosmic collision.Duncan Brown, Professor of Physics, Syracuse UniversityEdo Berger, Professor of Astronomy, Harvard UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/823742017-08-23T19:25:29Z2017-08-23T19:25:29ZFrom flatscreen TVs to your smartphone: the element boron deserves more attention<figure><img src="https://images.theconversation.com/files/182385/original/file-20170817-13456-yxzar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Boron is often ignored, but it's got a lot of important qualities.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/david44149/14002811915/in/photolist-6nyvxh-awXnMC-duL3Zq-c6E7ef-c6E825-c6E7nC-8sZN1w-2DLgBv-bx8ddc-bmMReq-c6E78w-b7iMzt-nko58D-hucmVJ-99RxeL-8zABdh-8zxskk-7o8Kcr-8zxsoZ-AFyjqN-4qkZcg-99Rxfo-8zAB3Q-x7Hxws">David Ellis/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Each time you watch sport on a flatscreen television, or send a message by touching your smartphone screen, give thanks to an unsung hero of the periodic table: boron.</p>
<p>Boron, often wrongly labelled a “boring” element, plays a versatile role in our lives. </p>
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<p>
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<strong>
Read more:
<a href="https://theconversation.com/the-periodic-table-from-its-classic-design-to-use-in-popular-culture-52822">The periodic table: from its classic design to use in popular culture</a>
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<p>It’s the key ingredient in borosilicate glass, which is known for its exceptional resistance to thermal change and chemicals, and its ability to withstand impact. This means glass cookware can go into a hot oven straight from the freezer, and that lab equipment such as beakers and test tubes can withstand corrosion.</p>
<p>Neodymium magnets, in which boron plays a role in the formation of the crystal structure and retaining magnetisation, are among the strongest permanent magnets commercially available. Boron is also used to prepare detergents, buffer solution, insecticides, insulation and semiconductors.</p>
<p>Australia’s soils can be <a href="http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0005/158864/boron-deficiency-pastures-field-crops.pdf">deficient in boron</a>, and boron-containing fertiliser is used to help with root growth and flowering.</p>
<p>Although I research boron chemistry for energy conversion and storage, the element has a rich history with many practical applications.</p>
<h2>What makes boron so special?</h2>
<p>Due to its reactivity, boron naturally exists only in combination with other elements, forming boric acid and inorganic salts known as borates. </p>
<p>One key reason why boron is so versatile is its electron-deficient nature, which means it’s very inclined to accept electrons from other elements and easily forms many interesting compounds with both metals and non-metals.</p>
<p>For example, metal borides, compounds formed between metal (M) and boron (B), such as rhenium diboride, have high hardness due to extensive B-B and M-B bonds. There’s also boron carbide, which is an extremely hard and light ceramic used in bullet proof vests and tank armour.</p>
<p>Boron-10 (10B), <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5296588/">a stable isotope</a> that can be isolated by extensive distillation of volatile boron compounds, has led to Boron Neutron Capture Therapy (BNCT) <a href="https://www.sciencedaily.com/releases/2011/03/110304091901.htm">that treats</a> locally invasive malignant tumours, such as recurrent head and neck cancer.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/182734/original/file-20170821-27160-7mpjkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182734/original/file-20170821-27160-7mpjkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=592&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182734/original/file-20170821-27160-7mpjkd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=592&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182734/original/file-20170821-27160-7mpjkd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=592&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182734/original/file-20170821-27160-7mpjkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=744&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182734/original/file-20170821-27160-7mpjkd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=744&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182734/original/file-20170821-27160-7mpjkd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=744&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A Boron Neutron Capture Therapy ADAM Injector with (L to R) Enrique Henestroza, Joe Kwan and Lou Reginato that constructed a proton accelerator that will be a key element in new brain cancer treatment.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/berkeleylab/3525773210/in/photolist-6nyvxh-awXnMC-duL3Zq-c6E7ef-c6E825-c6E7nC-8sZN1w-2DLgBv-hucmVJ-bx8ddc-bmMReq-c6E78w-99RxeL-AFyjqN-b7iMzt-nko58D-8zABdh-8zxskk-7o8Kcr-8zxsoZ-4qkZcg-99Rxfo-8zAB3Q-x7Hxws">Berkeley Lab</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Notably, the Nobel Prize for Chemistry has been awarded <a href="https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1976/press.html">at least</a> <a href="https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1979/">three times</a> to scientists working in the field of boron chemistry. </p>
<p>One recent contribution is the “Suzuki Coupling” reaction in 2010, <a href="http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2010/">which revolutionised</a> chemical synthesis and supports product developments such as Organic Light Emitting Display (OLED), which can be used for thin, colourful TVs.</p>
<h2>Boron versus carbon</h2>
<p>Boron and carbon are neighbouring elements in the periodic table and are similar in many ways. Carbon has arguably enjoyed greater publicity, however. Most recently, a lot of attention has been paid <a href="https://theconversation.com/harder-than-diamond-stronger-than-steel-super-conductor-graphenes-unreal-5123">to graphene</a> – one atomic layer of carbon atoms – which has many potential high-tech uses.</p>
<p>Similar to hydrocarbons, boron forms a series of neutral boranes that were once studied as rocket fuel because they produce an enormous amount of energy when reacting with oxygen. But they often proved toxic and too difficult to control.</p>
<p>Elemental boron exists <a href="https://books.google.com.au/books?id=FA7VAwAAQBAJ&pg=PT268&lpg=PT268&dq=boron+16+allotropes&source=bl&ots=XBVva5OMx_&sig=Z_tOoLzt1vkwIvye7wwqQ3ByhHE&hl=en&sa=X&ved=0ahUKEwiz_YG_xOzVAhVJNJQKHbQ7CScQ6AEIWzAJ#v=onepage&q=boron%2016%20allotropes&f=false">in 16 known</a> “allotropes” – different forms of the same element. Carbon has two common ones: diamond and graphite.</p>
<p>The difficulty in controlling the formation of desired boron allotropes slows down research. In contrast, carbon materials can be easily prepared and studied. </p>
<h2>A pivotal role in energy conversion and storage</h2>
<p>It is exciting to see scientists around the globe beavering away in labs, finding new ways to use this plucky little element.</p>
<p>Here are some of the big questions they’re tackling:</p>
<p><strong>1. Boron as a source of energy</strong></p>
<p>Some researchers are examining whether we can get energy from boron using <a href="https://www.nasa.gov/directorates/spacetech/niac/tarditi_aneutronic_fusion.html">aneutronic fusion</a> – a form of fusion power in which negligible amounts of neutrons are released.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/182735/original/file-20170821-27189-1uni6u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/182735/original/file-20170821-27189-1uni6u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/182735/original/file-20170821-27189-1uni6u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/182735/original/file-20170821-27189-1uni6u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/182735/original/file-20170821-27189-1uni6u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/182735/original/file-20170821-27189-1uni6u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/182735/original/file-20170821-27189-1uni6u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Boron.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/jcburns/20423064426/in/photolist-6nyvxh-awXnMC-duL3Zq-c6E7ef-c6E825-c6E7nC-8sZN1w-2DLgBv-hucmVJ-bx8ddc-bmMReq-c6E78w-99RxeL-AFyjqN-b7iMzt-nko58D-8zABdh-8zxskk-7o8Kcr-8zxsoZ-4qkZcg-99Rxfo-8zAB3Q-x7Hxws">J.C. Burns</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p><strong>2. Boron as an energy carrier</strong></p>
<p>Compounds containing boron, nitrogen and hydrogen can effectively store and transfer hydrogen. This is important because hydrogen is an ideal candidate <a href="http://pubs.rsc.org/en/content/articlelanding/2012/ee/c2ee23039a/unauth#!divRelatedContent&articles">to store energy</a> produced by wind farm and solar plants. </p>
<p>Sodium difluoro (oxalato) borate, on the other hand, can outperform some commercial compounds as an electrolyte salt for emerging sodium-ion batteries, which could be <a href="http://www.boronmolecular.com/Na-ionBatteryElectrolytes">a great candidate</a> for large-scale energy storage.</p>
<p><strong>3. Boron for heat conservation</strong></p>
<p>Some solar water heating and solar power generation plants are using borosilicate collector tubes to harness reflected radiation from mirrors, so the steam turbines can be driven in a more efficient way. </p>
<p>We have also seen more stringent building standards with respect to heat conservation, promoting the use of borates for fiberglass insulation.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-search-for-new-elements-on-the-periodic-table-started-with-a-blast-52862">The search for new elements on the periodic table started with a blast</a>
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<p>Impressed? </p>
<p>Should boron get more of the spotlight?</p>
<p>I’m sure we will see boron continue to be a star in our tech-driven society. From fertiliser to OLED screens, it’s poised to have a big impact.</p><img src="https://counter.theconversation.com/content/82374/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Zhenguo Huang receives funding from Australian Research Council and U.S. Borax. </span></em></p>Boron is the hidden ingredient in a lot of our technology. Get to know this plucky little element.Zhenguo Huang, Senior Research Fellow in Energy, University of WollongongLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/528222017-04-02T19:32:41Z2017-04-02T19:32:41ZThe periodic table: from its classic design to use in popular culture<figure><img src="https://images.theconversation.com/files/113029/original/image-20160226-26723-15gnsbs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The periodic table of the elements on a T-shirt.</span> <span class="attribution"><a class="source" href="http://mirror-au-nsw1.gallery.hd.org/_c/textures/_more2005/_more05/periodic-table-of-the-elements-printed-on-ancient-cotton-T-shirt-rotated-lowres-DHD.jpg.html">Damon Hart Davis</a></span></figcaption></figure><p>The periodic table is one of those classic images that you find in many science labs and classrooms. It’s an image almost everyone has seen at some time in their life.</p>
<p>You can also find the periodic table on <a href="https://www.questacon.edu.au/qshop/Questacon-Periodic-Table-T-shirt/">t-shirts</a>, <a href="http://shop.australiangeographic.com.au/mug-periodic-table.html">mugs</a>, <a href="https://www.getdigital.eu/Periodic-Table-Beach-Towel.html">beach towels</a>, <a href="https://www.amazon.com/Periodic-Chemical-Elements-Novelty-Pillowcase/dp/B00QFJXNVS">pillowcases</a> and <a href="http://www.cafepress.com.au/+periodic-table-chemical-elements+duvet-covers">duvet covers</a>, and <a href="http://www.cafepress.com.au/+periodic-table+gifts">plenty of other items</a>. It even inspired a <a href="https://www.theguardian.com/science/2009/oct/09/primo-levi-periodic-table">collection of short stories</a>. </p>
<p>Who can forget the periodic table put to music by the American <a href="http://www.allmusic.com/artist/tom-lehrer-mn0000611877/biography">Tom Lehrer</a>, a Harvard mathematics professor who was also a singer/songwriter and satirist. His song, The Elements, includes all the elements that were known at the time of writing in 1959.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/zGM-wSKFBpo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Since then, several new elements have been added to the periodic table, including the <a href="https://theconversation.com/four-new-elements-named-heres-how-the-periodic-table-evolved-60276">four</a> that were <a href="https://iupac.org/iupac-announces-the-names-of-the-elements-113-115-117-and-118/">formally approved last year</a> by the International Union of Pure and Applied Chemistry (IUPAC).</p>
<p>But what exactly does the periodic table show?</p>
<p>In brief, it is an attempt to organise the collection of the elements – all of the known pure compounds made from a single type of atom.</p>
<p>There are two ways to look at how the periodic table is constructed, based on either the observed properties of the elements contained within it, or on the subatomic construction of the atoms that form each element.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/155128/original/image-20170201-12656-1hd5emj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155128/original/image-20170201-12656-1hd5emj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/155128/original/image-20170201-12656-1hd5emj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=385&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155128/original/image-20170201-12656-1hd5emj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=385&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155128/original/image-20170201-12656-1hd5emj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=385&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155128/original/image-20170201-12656-1hd5emj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=484&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155128/original/image-20170201-12656-1hd5emj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=484&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155128/original/image-20170201-12656-1hd5emj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=484&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The basic modern periodic table.</span>
<span class="attribution"><span class="source">Shutterstock/duntaro</span></span>
</figcaption>
</figure>
<h2>The elements</h2>
<p>When scientists began collecting elements in the 1700s and 1800s, slowly identifying new ones over decades of research, they began to notice patterns and similarities in their physical properties. Some were gases, some were shiny metals, some reacted violently with water, and so on. </p>
<p>At the time when elements were first being discovered, the structure of atoms was not known. Scientists began to look at ways to arrange them systematically so that similar properties could be grouped together, just as someone collecting seashells might try to organise them by shape or colour.</p>
<p>The task was made more difficult because not all of the elements were known. This left gaps, which made deciphering patterns a bit like trying to assemble a jigsaw puzzle with missing pieces.</p>
<p>Different scientists came up with different types of tables. The first version of the current table is generally attributed to Russian chemistry professor <a href="http://www.britannica.com/biography/Dmitry-Ivanovich-Mendeleyev">Dmitri Mendeleev</a> in 1869, with an updated version in 1871.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/116741/original/image-20160330-28455-1ror2vj.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/116741/original/image-20160330-28455-1ror2vj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/116741/original/image-20160330-28455-1ror2vj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=350&fit=crop&dpr=1 600w, https://images.theconversation.com/files/116741/original/image-20160330-28455-1ror2vj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=350&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/116741/original/image-20160330-28455-1ror2vj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=350&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/116741/original/image-20160330-28455-1ror2vj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=439&fit=crop&dpr=1 754w, https://images.theconversation.com/files/116741/original/image-20160330-28455-1ror2vj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=439&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/116741/original/image-20160330-28455-1ror2vj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=439&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mendeleev’s periodic table is first published outside Russia in Zeitschrift für Chemie (1869, pages 405-6).</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Mendeleev%27s_periodic_table_(1869).svg">Wikimedia/Dimitri Mendeleev</a></span>
</figcaption>
</figure>
<p>Importantly, Mendeleev left gaps in the table where he thought missing elements should be placed. Over time, these gaps were filled in and the final version as we know it today emerged.</p>
<h2>The atoms</h2>
<p>To really understand the final structure of the periodic table, we need to understand a bit about atoms and how they are constructed. Atoms have a central core (the nucleus) made up of smaller particles called protons and neutrons.</p>
<p>It is the number of protons that gives an element its atomic number – the number generally found in the top left corner of each box in the periodic table. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/155129/original/image-20170201-12685-525wu2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155129/original/image-20170201-12685-525wu2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/155129/original/image-20170201-12685-525wu2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=195&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155129/original/image-20170201-12685-525wu2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=195&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155129/original/image-20170201-12685-525wu2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=195&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155129/original/image-20170201-12685-525wu2.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=245&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155129/original/image-20170201-12685-525wu2.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=245&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155129/original/image-20170201-12685-525wu2.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=245&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The properties of hydrogen as marked on the periodic table.</span>
<span class="attribution"><span class="source">Shutterstock/duntaro</span></span>
</figcaption>
</figure>
<p>The periodic table is arranged in order of increasing atomic number (left to right, top to bottom). It ranges from element 1 (hydrogen <a href="http://www.rsc.org/periodic-table/element/1/hydrogen">H</a>) in the top left, to the newly approved element 118 (oganesson <a href="http://www.rsc.org/periodic-table/element/118/oganesson">Og</a>) in the bottom right.</p>
<p>The number of neutrons in the nucleus can vary. This gives rise to different isotopes for every element. </p>
<p>For example, you may have heard of <a href="http://science.howstuffworks.com/environmental/earth/geology/carbon-14.htm">carbon-14 dating</a> to determine the age of objects. This isotope is a radioactive version of normal carbon <a href="http://www.rsc.org/periodic-table/element/6/carbon">C</a> (or carbon-12) that has two extra neutrons.</p>
<p>But why is there a separate box of elements below the main table, and why is the main table an odd shape, with a bite taken out of the top? That comes down to how the other component of the atom – the electrons – are arranged.</p>
<h2>The electrons</h2>
<p>We tend to think of atoms as built a bit like onions, with seven layers of electrons called “shells”, labelled K, L, M, N, O, P, and Q, surrounding the core nucleus.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/126483/original/image-20160614-29205-4s6tgg.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/126483/original/image-20160614-29205-4s6tgg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/126483/original/image-20160614-29205-4s6tgg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=318&fit=crop&dpr=1 600w, https://images.theconversation.com/files/126483/original/image-20160614-29205-4s6tgg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=318&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/126483/original/image-20160614-29205-4s6tgg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=318&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/126483/original/image-20160614-29205-4s6tgg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=399&fit=crop&dpr=1 754w, https://images.theconversation.com/files/126483/original/image-20160614-29205-4s6tgg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=399&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/126483/original/image-20160614-29205-4s6tgg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=399&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Think of the atom with a central nucleus that contains all the protons and neutrons, surrounded by a series of shells that contain the electrons.</span>
<span class="attribution"><span class="source">The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Each row in the periodic table sort of corresponds to filling up one of these shells with electrons. Each shell has subshells, and the order in which the shells/subshells get filled is based on the energy required, although it’s a complicated process. We’ll come back to these later.</p>
<p>In simple terms, the first element in each row starts a new shell containing one electron, while the last element in each row has two (or one for the the first row) of the subshells in the outer shell fully occupied. These differences in electrons also account for some of the similarities in properties between elements. </p>
<p>With the one or two subshells in the outer layer full of electrons, the last elements of each row are quite unreactive, as there are no holes or gaps in the outer shell to interact with other atoms.</p>
<p>This is why elements in the last column, such as helium <a href="http://www.rsc.org/periodic-table/element/2/helium">He</a>, neon (<a href="http://www.rsc.org/periodic-table/element/10/neon">Ne</a>), argon (<a href="http://www.rsc.org/periodic-table/element/18/argon">Ar</a>) and so on, are called the <a href="http://www.britannica.com/science/noble-gas">noble gases</a> (or inert gases). They are all gases and they are “noble” because they rarely associate with other elements.</p>
<p>In contrast, the elements of the first column, with the exception of hydrogen (just like English grammar, there’s always an exception!), are called alkali metals. The first-column elements are metal-like in character, but with only one electron in the outer shell, they are very reactive as this lone electron is very easy to engage in chemical bonding. When added to water, they quickly react to form an alkaline (basic) solution.</p>
<p>Each shell can accommodate an increasing number of electrons. The first shell (K) only fits two, so the first row of the periodic table has only two elements: hydrogen (<a href="http://www.rsc.org/periodic-table/element/1/hydrogen">H</a>) with one electron, and helium (<a href="http://www.rsc.org/periodic-table/element/2/helium">He</a>) with two.</p>
<p>The second shell (L) fits eight electrons. Thus the second row of the periodic table contains eight elements, with a gap left between hydrogen and helium to accommodate the extra six. </p>
<p>The third shell (M) fits 18 electrons, but the third row still only has eight elements. This is because the extra ten electrons don’t get added to this layer until after the first two electrons are added to the fourth shell (N) (we’ll get to why, later).</p>
<p>So the gap is expanded in the fourth row to accommodate the additional ten elements, leading to the “bite” out of the top of the table. The extra ten compounds in the middle section are called the <a href="http://www.britannica.com/science/transition-element">transition metals</a>.</p>
<p>The fourth shell holds 32 electrons, but again the extra electrons are not added to this shell until some have also been added to the fifth (O) and sixth (P) shells, meaning that both the fourth and fifth rows hold 18 elements. </p>
<p>For the next two rows (sixth and seventh), rather than further expanding the table sideways to include these extra 14 elements, which would make it too wide to easily read, they have been inserted as a block of two rows, called the <a href="http://www.britannica.com/science/lanthanoid">lanthanoids</a> (elements 57 to 71) and <a href="http://www.britannica.com/science/actinoid-element">actinoids</a> (elements 89 to 103), below the main table.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/154931/original/image-20170131-13243-135rr77.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/154931/original/image-20170131-13243-135rr77.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/154931/original/image-20170131-13243-135rr77.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=359&fit=crop&dpr=1 600w, https://images.theconversation.com/files/154931/original/image-20170131-13243-135rr77.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=359&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/154931/original/image-20170131-13243-135rr77.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=359&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/154931/original/image-20170131-13243-135rr77.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=451&fit=crop&dpr=1 754w, https://images.theconversation.com/files/154931/original/image-20170131-13243-135rr77.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=451&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/154931/original/image-20170131-13243-135rr77.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=451&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The periodic table would look very different if the lanthanoids and actinoids were inserted within the table.</span>
<span class="attribution"><span class="source">The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>You can see where they would fit in if the periodic table was widened, if you look at the bottom two squares in the third column of the table above.</p>
<h2>Across the columns</h2>
<p>There is another complicating factor leading to the final shape of the table. As mentioned earlier, as the electrons are added to each layer they go into different subshells (or orbitals), which describes locations around the nucleus where they are most likely to be found. These are known by the letters s, p, d and f.</p>
<p>The letters used for the orbitals are actually derived from descriptions of the emission or absorption of light due to electrons moving between the orbitals: <strong>s</strong>harp, <strong>p</strong>rincipal, <strong>d</strong>iffuse and <strong>f</strong>undamental.</p>
<p>Each shell has its own configuration of subshells named from 1s through to 7p, which gives the total number of electrons in each shell as we progress through the periodic table. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/163552/original/image-20170402-27256-u5wjt7.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/163552/original/image-20170402-27256-u5wjt7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/163552/original/image-20170402-27256-u5wjt7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=489&fit=crop&dpr=1 600w, https://images.theconversation.com/files/163552/original/image-20170402-27256-u5wjt7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=489&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/163552/original/image-20170402-27256-u5wjt7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=489&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/163552/original/image-20170402-27256-u5wjt7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=615&fit=crop&dpr=1 754w, https://images.theconversation.com/files/163552/original/image-20170402-27256-u5wjt7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=615&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/163552/original/image-20170402-27256-u5wjt7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=615&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>As mentioned earlier the order in which the subshells fill with electrons is not so straightforward. You can see the order in which they fill from the image below, just follow the order as you would read down from left to right.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/163745/original/image-20170403-21969-flm80p.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/163745/original/image-20170403-21969-flm80p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/163745/original/image-20170403-21969-flm80p.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=353&fit=crop&dpr=1 600w, https://images.theconversation.com/files/163745/original/image-20170403-21969-flm80p.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=353&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/163745/original/image-20170403-21969-flm80p.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=353&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/163745/original/image-20170403-21969-flm80p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=444&fit=crop&dpr=1 754w, https://images.theconversation.com/files/163745/original/image-20170403-21969-flm80p.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=444&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/163745/original/image-20170403-21969-flm80p.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=444&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>There is an <a href="http://www.ptable.com/#Orbital">interactive periodic table</a> that also illustrates the filling sequence well if you click through the atoms.</p>
<p>Elements within a column generally have similar properties, but in some places elements side by side can also be similar. For example, in the transition metals the cluster of precious metals around copper (<a href="http://www.rsc.org/periodic-table/element/29/copper">Cu</a>), silver (<a href="http://www.rsc.org/periodic-table/element/47/silver">Ag</a>), gold (<a href="http://www.rsc.org/periodic-table/element/79/gold">Au</a>), palladium (<a href="http://www.rsc.org/periodic-table/element/46/palladium">Pd</a>) and platinum (<a href="http://www.rsc.org/periodic-table/element/78/platinum">Pt</a>) are quite alike.</p>
<p>Most of the existing elements with high atomic numbers, including the <a href="https://theconversation.com/the-race-to-find-even-more-new-elements-to-add-to-the-periodic-table-52747">four superheavy elements added last year</a>, are very unstable and have never been detected in, or isolated from, nature. </p>
<p>Instead, they are created and analysed in minute quantities under highly artificial conditions. Theoretically, there could be further elements beyond the 118 now known (there are additional g, h and i suborbitals), but we don’t know yet if any of these would be stable enough to be isolated.</p>
<h2>A classic design</h2>
<p>The periodic table has seen many colourful and informative versions created over the years.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/150468/original/image-20161216-26116-qgzp6m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/150468/original/image-20161216-26116-qgzp6m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/150468/original/image-20161216-26116-qgzp6m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/150468/original/image-20161216-26116-qgzp6m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/150468/original/image-20161216-26116-qgzp6m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/150468/original/image-20161216-26116-qgzp6m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/150468/original/image-20161216-26116-qgzp6m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/150468/original/image-20161216-26116-qgzp6m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Periodic table decorates a taxi in the UK.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/gashwin/6959094671/">Flickr/Fr Gaurav Shroff</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>One of my favourites is an <a href="http://www.raci.org.au/periodic-table-on-show">artistic version</a> with original artworks for each element commissioned by the Royal Australian Chemical Institute to celebrate the International Year of Chemistry in 2011.</p>
<p>Another favourite is an <a href="http://www.periodictable.com/index.html">interactive version</a> with pictures of the elements. The creators of this site have also published a coffee table book called <a href="http://www.periodictable.com/Posters/index.theelements.html">The Elements</a> and an <a href="http://www.periodictable.com/Posters/index.theelementsipad.html">Apple app</a> with videos of each element.</p>
<p><a href="http://www.rsc.org/periodic-table">Interactive versions</a> have also been created by the Royal Society of Chemistry (and can also be downloaded as an app) and <a href="http://www.chemeddl.org/resources/ptl/index.php">ChemEd DL</a> among others.</p>
<p>The classic design of the periodic table can be used to play a version of the <a href="http://teachbesideme.com/periodic-table-battleship/">Battleship</a> game.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/118104/original/image-20160411-6250-1lbc5v4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/118104/original/image-20160411-6250-1lbc5v4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/118104/original/image-20160411-6250-1lbc5v4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/118104/original/image-20160411-6250-1lbc5v4.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/118104/original/image-20160411-6250-1lbc5v4.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/118104/original/image-20160411-6250-1lbc5v4.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/118104/original/image-20160411-6250-1lbc5v4.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/118104/original/image-20160411-6250-1lbc5v4.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Playing battleships with the periodic table at the first World Science Festival Brisbane in 2016.</span>
<span class="attribution"><span class="source">The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>There are also many fun versions created to help organise a multitude of objects, including <a href="http://grafikdzine.deviantart.com/art/Periodic-Food-Table-114678046">food</a>, <a href="http://beergeno.me/wp-content/uploads/2010/10/Per_iodic_Table_Beer_Styles.png">beer</a>, <a href="http://www.fastcocreate.com/3039715/ge-drops-some-social-science-with-the-periodic-table-of-emojis">emojis</a>, <a href="http://ictevangelist.com/wp-content/uploads/2014/07/PTAPPS-ICTEvangelist.png">iPad apps</a> and <a href="http://grosdino.deviantart.com/art/Periodic-Table-of-the-Birds-401058406">birds</a>.</p>
<p>As for Tom Lehrer’s The Elements, the song has yet to be updated to include all the elements known today but it has been covered by other people over the years. </p>
<p>Actor Daniel Radcliffe, of Harry Potter fame, performed a version during a guest appearance on the BBC’s Graham Norton Show.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/rSAaiYKF0cs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>There are <a href="https://www.youtube.com/watch?v=VgVQKCcfwnU">other musical versions</a> of the elements but they too have yet to be updated to include all entries of the periodic table.</p>
<p>In summary, the periodic table is the chemist’s taxonomy of all elements. Its triumph is that it is still highly relevant to scientists, while also becoming embedded in popular culture.</p><img src="https://counter.theconversation.com/content/52822/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Blaskovich receives funding from the Australian National Health and Medical Research Council (NHMRC) and the Wellcome Trust. He is a member of the Royal Australian Chemical Institute and the American Chemical Society.</span></em></p>The periodic table is one of the classic images of science that is found in labs as well as on t-shirts, mugs, even set to music. But what exactly is the periodic table?Mark Blaskovich, Senior Research Officer, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/643922016-09-09T08:59:35Z2016-09-09T08:59:35ZIn the global race for rare metals, Team China wins gold<figure><img src="https://images.theconversation.com/files/135491/original/image-20160825-6595-1byafcj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-354032012/stock-photo-a-pouch-with-scattered-gold-nugget-grains-on-cement-background.html?src=RaYq-GWcHM4SqisfjOmCmA-1-7">Shutterstock</a></span></figcaption></figure><p>Just as oil and gas has raised the stature of countries like Saudi Arabia in the <a href="http://www.bloomberg.com/news/articles/2015-04-12/saudi-arabia-s-plan-to-extend-the-age-of-oil">age of oil</a>, countries that dominate the production of metals are set to benefit similarly in the rare metal age. </p>
<p>Rare metals, which are <a href="https://theconversation.com/metals-in-your-smartphone-have-no-substitutes-21142">produced in limited amounts</a> and often in just a few countries, play critical roles in the next generation of products: they store power, provide luminescence and make <a href="http://www.cnet.com/uk/news/digging-for-rare-earths-the-mines-where-iphones-are-born/">products more efficient</a>. Tesla vehicles, iPhones, Boeing 787s and even night vision goggles rely on the specific properties of a host of difficult-to-pronounce obscure metals.</p>
<p>Because of the global explosion in high-tech wizardry, people rely on the production of <a href="https://www.bloomberg.com/view/articles/2015-10-22/global-economy-relies-on-tenuous-supply-lines-for-rare-metals">more metals on the periodic table than ever before</a>. And because of the high number of rare metals it takes to produce <a href="http://blogs.ei.columbia.edu/2012/09/19/rare-earth-metals-will-we-have-enough/">green products</a>, it’s no understatement to say that the <a href="http://www.nytimes.com/2015/11/20/opinion/the-next-resource-shortage.html">fate of the planet is tied to these materials</a>.</p>
<p>Over the Olympic season, countries rank their international stature on medal counts achieved during the games as a proxy for a country’s geopolitical stature. But the “real metal count” has a greater impact on the fate of nations.</p>
<p>To give an idea of how countries are doing, we produced two infographics to show the most notable changes in global producers from 1970 and 2015. It tallies the first, second, and third leading producers of all major and minor technology metals.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/135486/original/image-20160825-6588-1shlzy3.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/135486/original/image-20160825-6588-1shlzy3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/135486/original/image-20160825-6588-1shlzy3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=470&fit=crop&dpr=1 600w, https://images.theconversation.com/files/135486/original/image-20160825-6588-1shlzy3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=470&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/135486/original/image-20160825-6588-1shlzy3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=470&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/135486/original/image-20160825-6588-1shlzy3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=590&fit=crop&dpr=1 754w, https://images.theconversation.com/files/135486/original/image-20160825-6588-1shlzy3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=590&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/135486/original/image-20160825-6588-1shlzy3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=590&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">For each major mineral commodity, the world’s leading producer earns a gold medal, second leading producer a silver medal, and third leading producer a bronze medal. (Data source: USGS)</span>
<span class="attribution"><span class="source">Dylan McFarlane, Robert Pell, David Graham</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>From the metal tables you can see that no country has succeeded in the real metal race like China. Through geological good fortune, along with a sustained focus on the production of rare metals at lower costs than other countries, China is poised to reap the gains from their production. Their focus on producing these metals is important. Finding secure, stable supplies outside China is a goal of two international research projects, <a href="https://www.bgs.ac.uk/sosRare/home.html">SoS Rare</a> and <a href="http://www.bgs.ac.uk/hiTechAlkCarb/">HiTech AlkCarb</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/135487/original/image-20160825-6591-vs9z2q.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/135487/original/image-20160825-6591-vs9z2q.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/135487/original/image-20160825-6591-vs9z2q.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=426&fit=crop&dpr=1 600w, https://images.theconversation.com/files/135487/original/image-20160825-6591-vs9z2q.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=426&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/135487/original/image-20160825-6591-vs9z2q.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=426&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/135487/original/image-20160825-6591-vs9z2q.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=535&fit=crop&dpr=1 754w, https://images.theconversation.com/files/135487/original/image-20160825-6591-vs9z2q.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=535&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/135487/original/image-20160825-6591-vs9z2q.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=535&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">For each major mineral commodity, the world’s leading producer earns a gold medal, second leading producer a silver medal, and third leading producer a bronze medal. (Data source: USGS)</span>
<span class="attribution"><span class="source">Dylan McFarlane, Robert Pell, David Abraham</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Unlike Saudi Arabia, which sought riches from the sale of its resources, China seeks to capitalise on building downstream industries – for example, by making smartphones using home-produced components – through its industrial strategy: <a href="https://www.csis.org/analysis/made-china-2025">Made in China 2025</a>. These resources are then a great means to continue to expand their manufacturing prowess.</p>
<p><em><a href="http://www.davidsabraham.com/">David Abraham</a>, senior fellow at New America, assisted in the production of the piece.</em></p><img src="https://counter.theconversation.com/content/64392/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dylan McFarlane receives funding from the European Union's Horizon 2020 research and innovation programme under grant agreement 689909 for the HiTech AlkCarb project, a research project to develop new geomodels and sustainable exploration methods to target critical raw materials within alkaline igneous rocks and carbonatites. </span></em></p><p class="fine-print"><em><span>Robert Pell receives funding from NERC and the University of Exeter for the SoSRare project, a research project aiming to understand the mobility and concentration of rare earths in natural systems, and to investigate new processes that will lower the environmental impact of rare earth extraction and recovery.</span></em></p>iPhones, Boeing 787s, Teslas and a whole host of other technologies all rely on rare metals – so much so that a new era beckons.Dylan McFarlane, Research Project Manager in Critical Raw Materials and Responsible Mining, University of ExeterRobert Pell, Doctoral Candidate in Responsible Mining, University of ExeterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/608412016-06-09T17:23:34Z2016-06-09T17:23:34ZIt’s elemental: how to become a periodic table pub quiz champion<figure><img src="https://images.theconversation.com/files/125971/original/image-20160609-7049-130dk32.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What's in a name?</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/dl2_lim.mhtml?src=gb4wr4jug4vndzUhvhIPbg-1-9&clicksrc=download_btn_inline&id=369111563&size=medium_jpg&submit_jpg=">Shutterstock</a></span></figcaption></figure><p>With the naming of <a href="https://theconversation.com/four-new-elements-named-heres-how-the-periodic-table-evolved-60276">four new chemical elements</a>, it’s worth reflecting on their <a href="http://www.nndc.bnl.gov/content/elements.html">long and interesting history</a> – and you can become a pub quiz champion on the topic in the process. Indeed, while the periodic table may sound like a rather dry topic, it’s actually a subject packed full of the weird and wonderful.</p>
<p>The concept of discrete atoms was proposed by Robert Boyle in 1661, but in the first chemistry textbook, Traité élémentaire de chimie, published in that portentous, revolutionary year of 1789, <a href="http://gallica.bnf.fr/ark:/12148/btv1b8615746s/f15.image.r=.langEN">Antoine-Laurent de Lavoisier</a> listed a number of the chemical elements, including 27 known today. They included hydrogen, nitrogen, oxygen, phosphorus, sulfur, iron, zinc, mercury and gold.</p>
<p>Not that it did him any good. Lavoisier was guillotined during the Reign of Terror in 1794, the judge allegedly commenting <a href="https://www.acs.org/content/dam/acsorg/education/whatischemistry/landmarks/lavoisier/antoine-laurent-lavoisier-commemorative-booklet.pdf">“La République n'a pas besoin de savants ni de chimistes”</a> (“The Republic does not need scientists or chemists”).</p>
<p>It was Lavoisier’s contemporary, <a href="http://www.britannica.com/biography/Nicolas-Louis-Vauquelin">Louis Nicolas Vauquelin</a> who not only discovered the element <a href="http://www.rsc.org/periodic-table/element/4/beryllium">beryllium</a> in 1798 but also in 1803 synthesised the oxide of another new element. Finding it to be volatile, he gave it the baffling name “ptene”, derived from the Greek word for winged. Fortunately for posterity, this element is now known as <a href="http://www.rsc.org/periodic-table/element/76/osmium">osmium</a> (from the ozone-like smell of the oxide) and so far, no unpronounceable name has been adopted for any element.</p>
<h2>118: the magic number?</h2>
<p>Since the start of the 19th century, the number of known elements has steadily risen, reaching its present total of 118. <a href="http://www.world-nuclear.org/information-library/nuclear-fuel-cycle/introduction/what-is-uranium-how-does-it-work.aspx">Uranium</a> (number 92) is the heaviest element present in the Earth in an appreciable amount and all successive elements have been made in scientific laboratories. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/125972/original/image-20160609-7059-hru8f8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/125972/original/image-20160609-7059-hru8f8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=464&fit=crop&dpr=1 600w, https://images.theconversation.com/files/125972/original/image-20160609-7059-hru8f8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=464&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/125972/original/image-20160609-7059-hru8f8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=464&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/125972/original/image-20160609-7059-hru8f8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=583&fit=crop&dpr=1 754w, https://images.theconversation.com/files/125972/original/image-20160609-7059-hru8f8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=583&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/125972/original/image-20160609-7059-hru8f8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=583&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Nagasaki: the dark side or uranium.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/dl2_lim.mhtml?src=C6hNLn0UwzAfUtvW1n9kEA-1-6&clicksrc=download_btn_inline&id=251930701&size=medium_jpg&submit_jpg=">Shutterstock</a></span>
</figcaption>
</figure>
<p>The International Union of Pure and Applied Chemistry (IUPAC) has proposed names for <a href="http://iupac.org/cms/wp-content/uploads/2016/06/Press-Release_Naming-Four-New-Elements_8June2016.pdf">four recently synthesised chemical elements</a>, which complete the Periodic Table up to and including element 118.</p>
<p>Until now, this quartet have been known by their atomic numbers of 113, 115, 117 and 118 – or the temporary names of ununtrium (symbol Uut), ununpentium (Uup), ununseptium (Uus), and ununoctium (Uuo) respectively. The proposed names now are respectively nihonium (symbol Nh), moscovium (Mc), tennessine (Ts), and oganesson (Og).</p>
<p>Most elements have names ending in “–ium”. All but one of those are metals or metalloids; the one exception being <a href="http://www.rsc.org/periodic-table/element/2/helium">helium</a>, first discovered in the sun’s spectrum in 1868 and given its name from the Greek word for the sun – ἥλιος (helios) – before helium was identified on Earth (1895) and the character of the element could be known.</p>
<p>Two of these new elements are given names ending in –ium, though no one yet knows if they are metallic or not; the names of the other two are given endings appropriate to their positions in the Periodic Table. Tennessine is assigned to Group 17 (VIIB), together with the halogens fluorine, chlorine, bromine, iodine and astatine. Oganesson is in Group 18 (0), together with helium, neon, argon, krypton, xenon and radon.</p>
<p>The right to give a name to a newly discovered element is prestigious and has traditionally been seen to be in the hands of the discoverers. Four countries have contributed to the discoveries of new elements during the past half century. The work of the <a href="https://www.gsi.de/en/start/news.htm">German GSI Helmholtz Centre for Heavy Ion Research</a> at Darmstadt in discovering elements 107-112 – bohrium, meitnerium, hassium, darmstadtium, roentgenium and copernicum (as well as important confirmatory work on other elements) – is commemorated in their names. </p>
<p>As the leading German researcher Sigurd Hofmann <a href="http://www.popsci.com/scitech/article/2009-06/whats-it-name-element-periodic-table">commented</a>: </p>
<blockquote>
<p>We are being very democratic about naming. We are very careful, because these names last forever. We want the name to make sense now and forever – a famous scientist, famous lab, maybe a Greek philosopher.</p>
</blockquote>
<p>So don’t expect Boaty McBoatfacium just yet.</p>
<h2>What’s in a name?</h2>
<p>Of the four newest elements, two names are linked to Russia, one to Japan and one to the US, reflecting the international nature of the synthesis of these new man-made elements. But things have not always been like that.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/125973/original/image-20160609-7049-y0fkh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/125973/original/image-20160609-7049-y0fkh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/125973/original/image-20160609-7049-y0fkh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/125973/original/image-20160609-7049-y0fkh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/125973/original/image-20160609-7049-y0fkh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/125973/original/image-20160609-7049-y0fkh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/125973/original/image-20160609-7049-y0fkh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">And I shall name it…</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&autocomplete_id=&search_tracking_id=xnKAk0SAZ3_s0PwAjcsWUw&searchterm=chemical%20elementts&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=321825182">Shutterstock</a></span>
</figcaption>
</figure>
<p>Originally, this kind of nuclear synthesis was only carried out in the US at the <a href="http://www.berkeley.edu">University of California, Berkeley</a>, between 1940 and 1955, so they gave names to elements 93 (neptunium) to 101 (mendelevium). But the discovery of the next few elements was dominated by controversy, as both American and Soviet researchers were active, both schools claiming priority in discovery. The <a href="http://cenblog.org/newscripts/2011/08/whats-in-a-name-for-chemists-their-fields-soul/">Transfermium Wars</a> had begun, and it was not until the beginning of a new millennium that these names were sorted out by an <a href="http://www.degruyter.com/dg/viewarticle.fullcontentlink:pdfeventlink/$002fj$002fpac.1997.69.issue-12$002fpac199769122471$002fpac199769122471.pdf/pac199769122471.pdf?t:ac=j$002fpac.1997.69.issue-12$002fpac199769122471$002fpac199769122471.xml">international committee</a>.</p>
<p>Happily, international teams now work together to discover new chemical elements. Discoverers have often named a new element after their country, as with polonium (by Marie Curie) and americium, for example. Nihonium isn’t the first time that an element has taken its name from Japan. In 1909, the Japanese chemist Masataka Ogawa thought he had discovered element 43, and suggested that it be called <a href="http://pubs.acs.org/doi/abs/10.1021/ja01942a006">nipponium</a>.</p>
<p>But he hadn’t, so it wasn’t; we now know element 43 as technetium and it was not discovered until 1937. But it looks as if Ogawa had discovered a new element, rhenium, which was not recognised by others <a href="http://www.sciencedirect.com/science/article/pii/S0584854704001065">until 1925</a>.</p>
<h2>The whirligig of time</h2>
<p>Indeed, over the past centuries, many claims have been made in error for the discovery of elements; in most cases these have been <a href="http://www.rsc.org/chemistryworld/2015/02/lost-elements-periodic-table-shadow-side">innocent mistakes</a>, but a 1999 claim for the synthesis of elements 116 and 118 is now recognised to have involved fraud on the part of one of the <a href="http://physicsworld.com/cws/article/news/2001/aug/02/element-118-disappears-two-years-after-it-was-discovered">scientists involved</a>.</p>
<p>Not the least achievement of those who name compounds has been to set right historical injustices. <a href="http://www.atomicarchive.com/Bios/Meitner.shtml">Lise Meitner</a> was along with her colleague Otto Hahn a co-discoverer of <a href="http://www.bbc.co.uk/schools/gcsebitesize/science/add_aqa_pre_2011/radiation/nuclearfissionrev1.shtml">nuclear fission</a>, but did not share the award of the 1944 Nobel Prize in Chemistry for this; it went solely to Hahn. </p>
<p>In 1994, however, IUPAC recommended the adoption of the names hahnium and meitenerium for elements 108 and 109 respectively, commemorating them both. In the event, element 108 was named hessium, but element 109 was officially named meitnerium.</p>
<p>As Feste remarks in Twelfth Night, “And thus the whirligig of time brings in his revenges.” </p>
<p>All you have to do now is start revising.</p><img src="https://counter.theconversation.com/content/60841/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Cotton does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>As four new chemical elements are named, here’s all you need to know.Simon Cotton, Senior Lecturer in Chemistry, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/602762016-06-09T12:03:21Z2016-06-09T12:03:21ZFour new elements named – here’s how the periodic table evolved<p>The seventh row of the periodic table is complete, resplendent with <a href="http://iupac.org/cms/wp-content/uploads/2016/06/names-and-symbols-of-elements.pdf">four new names for the elements 113, 115, 117 and 118</a>. The International Union of Pure and Applied Chemistry (the organisation charged with naming the elements) has suggested these should be called nihonium (Nh); moscovium (Mc); tennessine (Ts) and oganesson (Og) and is expected to confirm the proposal in November.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/125867/original/image-20160609-7074-ypayh2.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/125867/original/image-20160609-7074-ypayh2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=911&fit=crop&dpr=1 600w, https://images.theconversation.com/files/125867/original/image-20160609-7074-ypayh2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=911&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/125867/original/image-20160609-7074-ypayh2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=911&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/125867/original/image-20160609-7074-ypayh2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1145&fit=crop&dpr=1 754w, https://images.theconversation.com/files/125867/original/image-20160609-7074-ypayh2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1145&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/125867/original/image-20160609-7074-ypayh2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1145&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Yuri Oganesyan.</span>
<span class="attribution"><span class="source">Kremlin.ru</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The three former elements are named after the regions where they were discovered (and Nihonium references <em>Nihon</em> the Japanese name for Japan). And “oganesson” is named after the Russian-American physicist Yuri Oganessian, who helped discover them.</p>
<p>After years of having to make do with temporary monikers while the elements were officially being added to the periodic table and evaluated by the IUPAC, these new names are much welcomed by scientists. Alas, those calling for names in tribute to great folk of popular culture have gone unheeded; <a href="https://thechronicleflask.wordpress.com/2016/01/06/name-element-117-octarine-in-honour-of-terry-pratchetts-discworld/">Octarine</a> (the colour of magic, according to Terry Pratchett), <a href="http://blog.oxforddictionaries.com/2016/01/new-chemical-elements-names/">Ziggium</a> (in tribute to David Bowie’s alter ego Ziggy Stardust) and Severium (in tribute to Alan Rickman and via Severus Snape) will not adorn the updated table. </p>
<p>Instead IUPAC have followed <a href="http://www.sciencealert.com/these-are-the-complicated-rules-that-dictate-how-new-elements-are-named">their rules</a> which stipulate that “elements are named after a mythological concept or character (including an astronomical object); a mineral, or similar substance; a place or geographical region; a property of the element; or a scientist”.</p>
<p>But there wasn’t always such an organisation overseeing the names of the elements. Most of them have come about <a href="http://pubs.acs.org/doi/abs/10.1021/ed064p472.4">via contorted etymologies</a>. So to give you an idea of the diversity of the most famous of scientific tables, I’ve turned it into an infographic and summarised a few of the eytmologies in numbers. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/125802/original/image-20160608-3485-pb9zno.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/125802/original/image-20160608-3485-pb9zno.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/125802/original/image-20160608-3485-pb9zno.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/125802/original/image-20160608-3485-pb9zno.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/125802/original/image-20160608-3485-pb9zno.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/125802/original/image-20160608-3485-pb9zno.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/125802/original/image-20160608-3485-pb9zno.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/125802/original/image-20160608-3485-pb9zno.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Periodic Table of Elements’ Etymology.</span>
<span class="attribution"><span class="source">Andy Bruning, Compound Interest</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><em><a href="https://universityofhull.box.com/s/03y9vjlwd8e2uekedb5wum98vl42597l" target="_blank">Click here for a larger version.</a></em></p>
<p><strong>Two</strong> of the elements stink. Bromine means “stench” and osmium means “smells”. France also appears twice on the periodic table in the form of francium and gallium (from Gaul) and its capital city, Paris, gets a mention (in the form of lutetium).</p>
<p><strong>Three</strong> sanskit words – <em>eka</em>, <em>dvi</em> and <em>tri</em>, meaning one, two and three – were prefixed to elements and used as provisional names for those that had yet to be discovered. Eka- is used to denote an element directly below another in the table, dvi- is for an element two rows down and tri- is three rows beneath. Russian chemist <a href="http://www.bbc.co.uk/schools/gcsebitesize/science/add_edexcel/atomic_structure/periodictablerev1.shtml">Dimitri Mendeleev</a> first used this nomenclature to fill in the gaps in his early periodic table, so element number 32 was known as eka-silicon until it was discovered and named germanium in 1886. Similarly, rhenium was known as dvi-manganese until 1926. Some 14 elements have had eka names including our four new additions which before their discovery were known as eka-thallium, eka-bismuth, eka-astitine and eka-radon.</p>
<p><strong>Four</strong> of the elements are named after planets (Earth – in the form of tellurium, Mercury, Neptune and Uranus). A further two are named after dwarf plants (Pluto and Ceres), while one after a star (helium from the Greek for the sun - Helios) and another after an asteroid (Pallas) feature on the periodic table. </p>
<p><strong>Five</strong> elements are named after other elements: molybdenium is from the Greek for lead, <em>molybdos</em>, while platinum comes from the Spanish <em>platina</em> meaning “little silver”. Radon is derived from radium, zirconium has its roots in the Arabic <em>zarkûn</em> meaning “gold-like” and nickle is from the German for “devil’s copper”.</p>
<p><strong>Eight</strong> elements were first isolated from rocks quarried in a the small village of Ytterby in Sweden. Four of those elements are named in tribute to the village (ytterbium, erbium, terbium, yttrium).</p>
<p><strong>15</strong> are named after scientists, only two of whom were women: Marie Curie and Lise Meitner are immortalised in curium and meitnerium.</p>
<p><strong>18</strong> elements have had placeholder names derived from the Latin for the elements atomic number (for example ununoctium, now oganesson). This was introduced to stop scientists fighting over what their discoveries should be called. Nobody wants a repeat of the three-decade long “<a href="http://www.academia.edu/3929798/The_Transfermium_Wars_IUPAC_and_the_Discovery_and_Naming_of_the_Transfermium_Elements">Transferium Wars</a>” when battles raged between competing American and Russian laboratories over what to call elements 104, 105 and 106. </p>
<p><strong>42</strong> elements’ names are derived from Greek; 23 from Latin; 11 from English; five are Anglo-saxon; five German; five Swedish; two Norse; three Russian, and one apiece for Japanese, Sanskrit, Gaelic, Arabic and Spanish.</p>
<p><strong>118</strong> elements appear on the periodic table, and the seventh row is complete, but that doesn’t mean the table is finished. Laboratories around the world are busy smashing atoms together in an attempt to <a href="http://www.wired.com/2016/01/smashing-new-elements-into-existence-gets-a-lot-harder-from-here/">forge new even heavier elements</a>. The hope is that before long these latter day alchemists will hit upon the fabled “<a href="http://arstechnica.com/science/2012/08/shell-game-why-heavier-atoms-might-get-stable-again/">island of stability</a>”; a region of the table that harbours elements with half-lives much longer that the sub-second lives of nihonium, moscovium, tennessine, and oganesson.</p>
<p>_Infographic for this article was made by Andy Brunning/<a href="http://www.compoundchem.com/2016/06/09/element-names/">Compound Interest</a></p><img src="https://counter.theconversation.com/content/60276/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Lorch is a member of the Royal Society of Chemistry.</span></em></p>Some 18 elements have had placeholder names derived from the Latin to stop scientists fighting over what their discoveries should be called.Mark Lorch, Professor of Science Communication and Chemistry, University of HullLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/565832016-04-07T20:05:57Z2016-04-07T20:05:57ZKitchen Science: everything you eat is made of chemicals<figure><img src="https://images.theconversation.com/files/117592/original/image-20160406-28935-1ml0tol.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Chemicals or a spice rack? Or both?</span> <span class="attribution"><span class="source">Hans Splinter/Flickr</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p><em>This is the first in our ongoing Kitchen Science series exploring the physics, chemistry and biology that takes place in your home.</em></p>
<hr>
<p><a href="http://www.chemfreecom.com/">Earnest websites</a>, <a href="https://www.theguardian.com/science/blog/2008/aug/06/dodgyscienceintvadverts">advertisements</a> and well-meaning <a href="http://www.mamamia.com.au/chemicals-affecting-childs-brain/">popular articles</a> routinely warn us about nasty “chemicals” lurking in our homes and kitchens. Many tout the benefits of switching to a “<a href="http://chemical-free-living.com/">chemical-free lifestyle</a>”. </p>
<p>The problem is: the word “chemical” is entirely misused in these contexts. <em>Everything</em> is a chemical – common table salt (sodium chloride), for instance, and even water (<a href="http://www.dhmo.org/truth/Dihydrogen-Monoxide.html">dihydrogen oxide</a>).</p>
<p>The chemicals in our diet are often put into four broad categories: carbohydrates, proteins, fats and lipids, and everything else. This final group has no defining characteristics but includes vitamins, minerals, pharmaceuticals and the hundreds of trace chemicals each of us consumes every day. </p>
<p>Of course, there are toxic and harmful chemicals, but just as many are completely fine for human consumption. So here’s a handy guide to the chemicals in your kitchen and what they mean for your health.</p>
<h2>The macronutrient chemicals</h2>
<p>Proteins, lipids (such as fats) and carbohydrates are known as the macronutrients. These provide most of our daily energy needs. </p>
<p>Despite <a href="https://theconversation.com/the-race-to-find-even-more-new-elements-to-add-to-the-periodic-table-52747">118 known elements</a> in the <a href="http://www.iupac.org/fileadmin/user_upload/news/IUPAC_Periodic_Table-8Jan16.pdf">periodic table</a>, these three categories predominantly contain just four elements – carbon, hydrogen, oxygen and nitrogen – with trace amounts of the remaining elements.</p>
<p>Chemicals called amino acids link together to create proteins. The richest sources include meat and eggs, but significant amounts are also found in beans, legumes and wheat flour.</p>
<p>Carbohydrates contain just carbon, hydrogen and oxygen atoms, all connected in very particular ways. “Carbs” include sugars, starch and cellulose, all of which are digested differently.</p>
<p>While sugars are one type of carbohydrate, artificial sweeteners, such as <a href="https://theconversation.com/sweet-news-no-evidence-that-artificial-sweetener-aspartames-bad-for-you-12608">aspartame</a> and saccharin, are not actually carbohydrates. </p>
<p>Despite concerns about the <a href="http://www.globalhealingcenter.com/natural-health/two-of-the-most-dangerous-artificial-sweeteners/">health effects of artificial sweeteners</a>, the health spotlight has recently been on the natural sweeteners: the <em>sugars</em>. White sugar (sucrose) and high-fructose corn syrup (a mixture of fructose and glucose) have been linked to a <a href="https://theconversation.com/sugar-isnt-just-empty-fattening-calories-its-making-us-sick-49788">range of widespread health conditions</a>.</p>
<p>Just like carbs, fats only contain carbon, hydrogen and oxygen, but gram for gram release more than twice the dietary energy of either protein or the carbs. Perhaps it’s for this reason fats have copped a lot of bad press for longer than the sugars. Nevertheless, some fat is essential for a healthy diet.</p>
<h2>Acids and bases</h2>
<p>Acid sounds bad. But there are many acids sitting benignly in our pantries and fridges.</p>
<p>Consider varieties of food and drink that are acidic. A classic example we often hear is that Coca-Cola has a pH value of about 3.2 (lower means more acidic, with 7 being neutral). That’s strong enough to remove rust from metal. And it’s true, thanks to the phosphoric acid in Coke. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/d5vZdhB9HcY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Watch as Coke eats away at surface rust.</span></figcaption>
</figure>
<p>As it happens, the human stomach also contains phosphoric acid (as well as hydrochloric acid), and this has an even stronger acidic pH value. Actually, apples and oranges have a similar pH value to Coke, and lemon juice is ten times more acidic.</p>
<p>The acidic characteristics of food and drink combine with other chemicals to provide flavour. Without some acidic character, many foods would be bland.</p>
<p>Chemically speaking, the opposite of acidic is known as basic, or alkali. While acidic substances have a pH of less than 7, basic foods have a pH greater than 7. Examples of basic foods from the kitchen are fewer, but include eggs, some baked products like cakes and biscuits, and bicarb soda.</p>
<h2>Toxic chemicals in the kitchen</h2>
<p>Obviously, there are also toxic chemicals lurking in our kitchen cupboards. But these are usually kept under the sink and often have pH values at the extreme ends of the spectrum. </p>
<p>Cleaning products such as ammonia and lye (i.e. Drano) are very basic. Soaps and detergents are also at the basic end of the scale.</p>
<p>Acidic cleaning solutions are also common, such as concentrated sulfuric acid, which can also be used to unblock drains.</p>
<h2>Cooking is chemistry</h2>
<p>Cooking itself is really just chemistry. Heating, freezing, mixing and blending are all processes used in the laboratory and the kitchen. </p>
<p>When we cook food, a myriad of different physical and chemical processes simultaneously take place to transform the ingredients (i.e. chemicals) involved. </p>
<p>Carbohydrates are an interesting case study. Simple sugars combine with proteins in the <a href="http://www.scienceofcooking.com/maillard_reaction.htm">Maillard reaction</a>, which is responsible for browning food when it’s cooked. Add a little more heat and caramelisation takes over, while too much heat for too long leads to burnt flavours. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/117594/original/image-20160406-28945-1kr3phz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/117594/original/image-20160406-28945-1kr3phz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/117594/original/image-20160406-28945-1kr3phz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/117594/original/image-20160406-28945-1kr3phz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/117594/original/image-20160406-28945-1kr3phz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/117594/original/image-20160406-28945-1kr3phz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/117594/original/image-20160406-28945-1kr3phz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/117594/original/image-20160406-28945-1kr3phz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It takes some deft chemistry to make a seasoned smoked brisket.</span>
<span class="attribution"><span class="source">jeffreyw/Flickr</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Starch is another carbohydrate well known for its ability to create gels, such as in a panna cotta. Upon heating, powdered starch combines with water and a completely different texture is created.</p>
<p>So next time you hear someone say “I don’t like to put chemicals into my body”, feel free to chuckle. <em>Everything</em> is made of chemicals. We’d be in a bit of strife without chemicals, not least in the kitchen.</p>
<p><em>This article is part of the <a href="https://theconversation.com/au/topics/kitchen-science">Kitchen Science</a> series, exploring the amazing physics and chemistry going on in our kitchens every day. If you’re an academic with an idea for a Kitchen Science article, <a href="mailto:tim.dean@theconversation.edu.au">get in touch!</a></em></p><img src="https://counter.theconversation.com/content/56583/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Thompson is affiliated with Monash University and the Chemistry Education Association. </span></em></p>Chemicals have a bad rap these days. But the fact is that everything is made of chemicals. Here are some of the chemicals at work in your kitchen.Chris Thompson, Lecturer in Chemistry, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/528622016-01-07T05:46:10Z2016-01-07T05:46:10ZThe search for new elements on the periodic table started with a blast<figure><img src="https://images.theconversation.com/files/107484/original/image-20160107-14970-1tvxwlo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">New elements were discovered in early thermonuclear bomb tests.</span> <span class="attribution"><a class="source" href="https://pixabay.com/en/nuclear-weapons-test-nuclear-weapon-67557/">Pixabay</a></span></figcaption></figure><p>So the periodic table has expanded again with the addition late last year of <a href="https://theconversation.com/the-race-to-find-even-more-new-elements-to-add-to-the-periodic-table-52747">four new superheavy elements</a>, bringing the known total up to 118.</p>
<p>But the hunt for new elements started with efforts to develop nuclear power and the atomic bomb during World War II. At the time, <a href="http://www.rsc.org/periodic-table/element/92/uranium">uranium</a> was the heaviest known element, sitting at number 92 in the periodic table. </p>
<p>Researchers quickly discovered that when uranium is placed in a nuclear reactor, a complex sequence of interactions leads to the production of several so-called <a href="http://www.britannica.com/science/transuranium-element">transuranic elements</a> (elements beyond uranium).</p>
<p>Probing around in the debris of the first hydrogen bomb test revealed two further transuranic elements, <a href="http://www.rsc.org/periodic-table/element/99/einsteinium">einsteinium</a> and <a href="http://www.rsc.org/periodic-table/element/100/fermium">fermium</a>, bringing the total to an even 100. </p>
<p>Some of these elements are more commonly encountered that you might think. Most families would own some <a href="http://www.rsc.org/periodic-table/element/95/americium">americium</a> (element number 95) in the form of an every-day smoke detector, and <a href="http://www.rsc.org/periodic-table/element/98/californium">californium</a> (number 98) is widely used in industrial analysers. At a cool <a href="http://web.ornl.gov/%7Ewebworks/cpr/pres/107270_.pdf">US$60 million dollars per gram</a>, however, californium is about a million times more expensive than gold.</p>
<h2>Beyond the century element</h2>
<p>Beyond element 100, not even a hydrogen bomb is powerful enough to make progress, and scientists had to change tack in their quest for ever heavier elements. They substituted finesse for brute force, using particle accelerators to fire atoms onto carefully chosen targets. </p>
<p>Under the right conditions, the nuclei of atoms in the beam and target can fuse together and produce new elements. Fittingly, the first element made in this way, <a href="http://www.rsc.org/periodic-table/element/101/mendelevium">mendelevium</a>, was named after Dimitri Mendeleev, the creator of the periodic table.</p>
<p>Russian and American scientists continued to push forward through the 1950s, 60s and 70s, eventually reaching element <a href="http://www.rsc.org/periodic-table/element/106/seaborgium">106</a>. Reflecting the tensions of the Cold War years, priority for discovering these elements was strongly contested, with claims and counterclaims over ambiguous experimental results.</p>
<p>Not until 1997 did the International Union of Pure and Applied Chemistry (<a href="http://www.iupac.org/">IUPAC</a>) credit the discoverers of these elements and announce official names, mostly based on US and Soviet scientists and cities.</p>
<p>The Germans picked up the baton in the 1980s and 90s, discovering elements <a href="http://www.rsc.org/periodic-table/element/107/bohrium">107</a> through to <a href="http://www.rsc.org/periodic-table/element/112/copernicium">112</a>.</p>
<p>German researchers added a strongly European flavour to the naming scheme, honouring the physicists Niels Bohr (<a href="http://www.rsc.org/periodic-table/element/107/bohrium">bohrium</a>), Lise Meitner (<a href="http://www.rsc.org/periodic-table/element/109/meitnerium">meitnerium</a>), and Wilhelm Röntgen (<a href="http://www.rsc.org/periodic-table/element/111/roentgenium">roentgenium</a>), the astronomer Nicolaus Copernicus (<a href="http://www.rsc.org/periodic-table/element/112/copernicium">copernicium</a>) and their home city and state – <a href="http://www.rsc.org/periodic-table/element/110/darmstadtium">darmstadtium</a> and <a href="http://www.rsc.org/periodic-table/element/108/hassium">Hassium</a> are named after the town of Darmstadt and the German state of Hesse (passing through Latin along the way, which changes the ‘e’ to an ‘a’. Nothing’s ever simple!).</p>
<p>Only a handful of atoms of these elements have ever been produced.</p>
<h2>Let’s get super-heavy</h2>
<p>Moving on to still heavier elements, the hunt becomes increasingly difficult for three reasons.</p>
<p>First, the probability of two nuclei successfully fusing to form a new element rapidly decreases. Second, these super-heavy elements are extremely unstable, so any atoms produced have a fleeting existence. And third, it becomes increasingly difficult to untangle the complex signatures that reveal their momentary creation and decay.</p>
<p>Reflecting improved international relations in the post-Glasnost era, most of the recent discoveries have been credited to collaborations between US and Russian researchers. Elements 114 (<a href="http://www.rsc.org/periodic-table/element/114/flerovium">flerovium</a>) and 116 (<a href="http://www.rsc.org/periodic-table/element/116/livermorium">livermorium</a>) were announced by the IUPAC in 2012.</p>
<p>The <a href="http://www.iupac.org/news/news-detail/article/discovery-and-assignment-of-elements-with-atomic-numbers-113-115-117-and-118.html">most recent announcement</a> awards discovery of elements <a href="http://www.rsc.org/periodic-table/element/115/">115</a>, <a href="http://www.rsc.org/periodic-table/element/117/">117</a> and <a href="http://www.rsc.org/periodic-table/element/118/">118</a> to the same groups. A Japanese team, working independently, has been recognised for element <a href="http://www.rsc.org/periodic-table/element/113/">113</a>.</p>
<p>Producing even a sniff of these super-heavy elements is a heroic endeavour. To discover element 118, for example, experimenters fired a beam of calcium atoms for months at a time onto a target loaded with the element californium.</p>
<p>The odds of any one calcium atom fusing is tiny, roughly the same as winning the Oz Lotto jackpot, but then being killed by a lightning strike 15 minutes later.</p>
<p>The work resulted in just three atoms of the new element, each of which lasted for about 1000th of a second. Registering these atoms is just as difficult: a sophisticated detector system is need to pick up the cascade of radioactive decays which end with the atomic nucleus blowing itself apart.</p>
<h2>Why the search for new elements?</h2>
<p>All of which begs the question: why bother? After all, it’s hard to come up with a practical use for an element that takes so much effort to produce and lasts for so short a time.</p>
<p>Studying these super-heavy elements can teach us not only about the forces involved in atomic nuclei, but perhaps surprisingly, also about what goes on when stars die. </p>
<p>When a massive star explodes as a supernova, the extreme conditions could be just right for producing super-heavy elements. There are theoretical hints that some of these elements may buck the trend of increasing instability and exist in long-lived forms, an effect known as “<a href="http://www.superheavies.de/english/research_program/highlights_element_117.htm#The%20island%20of%20stability">the island of stability</a>”.</p>
<p>Current earth-bound experiments are just probing the shores of this island, but will help us determine whether these super-heavy elements could already be present in the universe. Searches in terrestrial rocks and in debris from space have so far drawn a blank, but researchers continue to hunt.</p>
<p>The four new additions to the periodic table have only temporary names at the moment. Rights for naming them go to the discoverers, although the IUPAC imposes strict rules.</p>
<p>Japonium has been suggested as a candidate for element 113, which would make it the first element starting with J. Now if scientists can just come up with a good name starting with Q, the periodic table would be alphabetically complete.</p><img src="https://counter.theconversation.com/content/52862/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Tickner does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>New elements found in the reactions of nuclear tests during World War II sparked the hunt for additions to the periodic table.James Tickner, Team Leader, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/527472016-01-05T05:58:20Z2016-01-05T05:58:20ZThe race to find even more new elements to add to the periodic table<figure><img src="https://images.theconversation.com/files/107236/original/image-20160105-28994-t3don9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The expanding periodic table of elements.</span> <span class="attribution"><span class="source">Shutterstock/Olivier Le Queinec</span></span></figcaption></figure><p>In an event likely never to be repeated, four new superheavy elements were last week <em>simultaneously</em> added to the periodic table. To add four in one go is quite an achievement but the race to find more is ongoing.</p>
<p>Back in 2012, the International Unions of Pure and Applied Chemistry (<a href="http://www.iupac.org/">IUPAC</a>) and Pure and Applied Physics (<a href="http://iupap.org/">IUPAP</a>) tasked five independent scientists to assess claims made for the discovery of elements 113, 115, 117 and 118. The measurements had been made at Nuclear Physics Accelerator laboratories in Russia (Dubna) and Japan (RIKEN) between 2004 and 2012. </p>
<p>Late last year, on December 30, 2015, IUPAC <a href="http://www.iupac.org/news/news-detail/article/discovery-and-assignment-of-elements-with-atomic-numbers-113-115-117-and-118.html">announced</a> that claims for the discovery of <em>all four</em> new elements had been accepted. </p>
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<a href="https://images.theconversation.com/files/30569/original/47ybnrd5-1378164128.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/30569/original/47ybnrd5-1378164128.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/30569/original/47ybnrd5-1378164128.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=329&fit=crop&dpr=1 600w, https://images.theconversation.com/files/30569/original/47ybnrd5-1378164128.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=329&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/30569/original/47ybnrd5-1378164128.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=329&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/30569/original/47ybnrd5-1378164128.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=413&fit=crop&dpr=1 754w, https://images.theconversation.com/files/30569/original/47ybnrd5-1378164128.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=413&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/30569/original/47ybnrd5-1378164128.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=413&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The completed seventh row in the periodic table.</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
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<p>This completes the seventh row of the periodic table, and means that all elements between hydrogen (having only one proton in its nucleus) and element 118 (having 118 protons) are now officially discovered.</p>
<p>After the excitement of the discovery, the scientists now have the naming rights. The Japanese team will suggest the name for element 113. The joint Russian/US teams will make suggestions for elements 115, 117 and 118. These names will be assessed by IUPAC, and once approved, will become the new names that scientists and students will have to remember.</p>
<p>Until their discovery and naming, all superheavy elements (up to 999!) have been assigned temporary names by the IUPAC. Element 113 is known as ununtrium (Uut), 115 is ununpentium (Uup), 117 is ununseptium (Uus) and 118 ununoctium (Uuo). These names are not actually used by physicists, who instead refer to them as “element 118”, for example.</p>
<h2>The superheavy elements</h2>
<p>Elements heavier than Rutherfordium (element 104) are referred to as superheavy. They are not found in nature, because they undergo radioactive decay to lighter elements.</p>
<p>Those superheavy nuclei that have been created artificially have decay lifetimes between nanoseconds and minutes. But longer-lived (more neutron-rich) superheavy nuclei are expected to be situated at the centre of the so-called “<a href="http://www.superheavies.de/english/research_program/highlights_element_117.htm#The%20island%20of%20stability">island of stability</a>”, a place where neutron-rich nuclei with extremely long half-lives should exist.</p>
<p>Currently, the isotopes of new elements that have been discovered are on the “shore” of this island, since we cannot yet reach the centre. </p>
<h2>How were these new elements created on Earth?</h2>
<p>Atoms of superheavy elements are made by nuclear fusion. Imagine touching two droplets of water – they will “snap together” because of surface tension to form a combined larger droplet. </p>
<p>The problem in the fusion of heavy nuclei is the large numbers of protons in both nuclei. This creates an intense repulsive electric field. A heavy-ion accelerator must be used to overcome this repulsion, by colliding the two nuclei and allowing the nuclear surfaces to touch. </p>
<p>This is not sufficient, as the two touching spheroidal nuclei must change their shape to form a compact single droplet of nuclear matter – the superheavy nucleus.</p>
<p>It turns out that this only happens in a few “lucky” collisions, as few as one in a million.</p>
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<figcaption><span class="caption">Superheavy reaction fails to fuse (ANU)</span></figcaption>
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<p>There is yet another hurdle; the superheavy nucleus is very likely to decay almost immediately by fission. Again, as few as one in a million survives to become a superheavy atom, identified by its unique radioactive decay. </p>
<p>The process of superheavy element creation and identification thus requires large-scale accelerator facilities, sophisticated magnetic separators, efficient detectors and <em>time</em>. </p>
<p>Finding the three atoms of element 113 in Japan took 10 years, and that was <em>after</em> the experimental equipment had been developed.</p>
<p>The payback from the discovery of these new elements comes in improving models of the atomic nucleus (with applications in nuclear medicine and in element formation in the universe) and testing our understanding of atomic relativistic effects (of increasing importance in the chemical properties of the heavy elements). It also helps in improving our understanding of complex and irreversible interactions of quantum systems in general.</p>
<h2>The Australian connection in the race to make more elements</h2>
<p>The race is now on to produce elements 119 and 120. The projectile nucleus Calcium-48 (Ca-48) – successfully used to form the newly accepted elements – has too few protons, and no target nuclei with more protons are currently available. The question is, which heavier projectile nucleus is the best to use. </p>
<p>To investigate this, the leader and team members of the German superheavy element research group, based in Darmstadt and Mainz, recently travelled to the Australian National University.</p>
<p>They made use of unique ANU <a href="http://physics.anu.edu.au/nuclear/hiaf.php">experimental capabilities</a>, supported by the Australian Government’s <a href="https://www.education.gov.au/national-collaborative-research-infrastructure-strategy-ncris">NCRIS program</a>, to measure fission characteristics for several nuclear reactions forming element 120. The results will guide future experiments in <a href="http://www-win.gsi.de/tasca/Default.htm">Germany</a> to form the new superheavy elements.</p>
<p>It seems certain that by using similar nuclear fusion reactions, proceeding beyond element 118 will be more difficult than reaching it. But that was the feeling after the discovery of element 112, first observed in 1996. And yet a new approach using Ca-48 projectiles allowed another six elements to be discovered. </p>
<p>Nuclear physicists are already exploring different types of nuclear reaction to produce superheavies, and some promising results have already been achieved. Nevertheless, it would need a huge breakthrough to see four new nuclei added to the periodic table at once, as we have just seen.</p><img src="https://counter.theconversation.com/content/52747/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Hinde receives funding from the Australian Research Council.</span></em></p>They might only last for a fraction of a second but four new elements have finally won their place in the periodic table. The hunt is now on to find even more.David Hinde, Director, Heavy Ion Accelerator Facility, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.