The discovery of four new elements and the subsequent completion of the seventh row of the periodic table, has chemists all over the world excited. Back in 2011, we saw the discovery of elements 114 (flerovium) and 116 (livermorium), both in row seven. Now, on the 30th of December 2015 the elements 113, 115, 117 and 118 were verified by the International Union of Pure and Applied Chemistry (IUPAC) to join them. Hoorah!
The periodic table was developed by Russian scientist Dmitri Mendeleev in 1869, and places the elements in order of relative atomic mass. Mendeleev was also able to predict properties of undiscovered elements and left spaces in his table for such elements. Scientists had predicted these newly discovered elements’ existence long ago; their physical identification was long awaited, so there was no real element of surprise.
The elements are not naturally occurring, but created artificially by colliding light nuclei together, then tracking the decay of the superheavy elements that result from the collision. Element 113 for example, was discovered by colliding zinc ions with bismuth, at a tenth of the speed of light. From then an atom of element 113 exists for a fraction of a second.
The discoveries of elements has arguably been a global effort. Element 118 was discovered by a collaboration between the Joint Institute for Nuclear Research (Dubna, Russia) and the Lawrence Livermore National Laboratory (California, U.S), the same collaboration responsible for identifying 114 and 116. This was then joined by the Oak Ridge National Laboratory (Oak Ridge, Tennessee) for the discovery of elements 115 and 117. Element 113 on the other hand was found by Japanese scientists at the Riken Institute (Wako, Japan).
Following the official verification of the elements by IUPAC, the teams responsible for the elements discovery now have the opportunity to give the element a name and its chemical symbol, and this will be presented for public review for 5 months. According to IUPAC recommendations, elements can be named after a mythological concept/character, a mineral, a place, a property of the element or a scientist. There is speculation at present that the Riken Institute may opt for naming element 113 ‘Japanium’.
So our beloved table is now complete, and our over-expensive science textbooks are officially out of date. There have been suggestions that the Riken Institute are now searching for elements 119 and beyond, but even if this is possible, it won’t be for a long while yet. For now at least, we should bask in the satisfaction that row seven and, at least for now, the Periodic Table is finally complete.