Currently known by the temporary name Ununpentium, element 115 has been hunted for years. It was first believed to have been created in 2003 by a team led by Yuri Oganessian at the Joint Institute for Nuclear Research, Russia. They believed they had created a single atom of 115 by bombarding the element Americium with Calcium atoms. Americium has an atomic number of 95 while Calcium is made up of 20 protons, which means the two can be smashed together at high speed in an accelerator to make element 115. The atom they created was – like most superheavy elements with a mass greater than Uranium (92) – extremely unstable, and decayed immediately into several lighter elements.
Unfortunately for Oganessian and his team, the International Union of Pure and Applied Chemistry (IUPAC) – the body responsible for confirming element discoveries – called the results ‘inconclusive’. Now, Dirk Rudolph and his team from Lund University, Sweden, have created 30 atoms of element 115 using a similar technique, detailed in the journal Physical Review Letters. The atoms were identified through the x-rays that are given off when an atom decays. These x-rays are unique, like a fingerprint for the element, and may convince the IUPAC committee to ratify the discovery. Should they do so, Rudolph and his team will be allowed to recommend a name for element 115.
There is, however, a reason beyond simple bragging rights for scientists to hunt down new elements. It has been theorised for some time now that there will come a point where the increased size of the atom will actually cause it to become stable, and not radioactive: these theoretical elements are said to exist on the ‘island of stability’. It was thought at one time that element 115 may be on this island, but the Russian tests in 2003 disproved this. New thinking is that the island will appear at an atomic mass of 120, and should it be found scientists are confident that there will be some useful application.