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Getting Elemental: Four Elements Added to the Periodic Table

The chart hanging on the wall in your old chemistry classroom showing the periodic table of elements is now in need of an update.

In an unprecedented administrative move, the International Union of Pure and Applied Chemistry (IUPAC) announced at the end of 2015 that sufficient evidence exists to add four new elements – atomic numbers 113, 115, 117, and 118 – to the official reference known as the periodic table.
 
The search for new, unknown elements is an increasingly difficult yet ongoing area of research. Heavy nuclei such as these with large atomic numbers are inherently unstable, and live for mere fractions of a second before decaying into more stable byproducts. They are artificially created using the most advanced high-energy particle colliders that smash together lighter elements and search for characteristic atomic signatures in the results.
 
Confirming the existence of these elements is a statistical process. The RIKEN project team in Japan first claimed discovery of element 113 back in 2004, and followed up that claim with further evidence in 2012. Other researchers also claimed discovery of 113, but priority was given to the Japanese scientists by IUPAC.
 
Elements 115 and 117 are credited to a collaboration between a Russian research institute, the Joint Institute for Nuclear Research, and two U.S. facilities, Lawrence Livermore Laboratory in California and Oak Ridge National Laboratory in Tennessee. A separate partnership between the same Russian group and Livermore share credit for element 118, with research dating back to 2006.
 
The discovery of any new element is a very rare and significant scientific event. However, confirming the existence of four elements simultaneously is not as noteworthy as what these four closely associated elements represent. The rather odd layout of the periodic table is deliberate: Each row and column is meant to reflect the physical structure of each element’s atom and the grouping of their included electrons, from which are derived their chemical and atomic properties.
 
Along with the confirmation of flerovium (114) and livermorium (116) as recently as 2012, these four new elements complete Period 7 (the seventh and bottom row) of the table, providing a complete “family portrait” of these transuranium elements. The elements also close out Group III through Group VIII (the vertical columns) of elements sharing similar characteristics.
 
The next step in research is to find elements with atomic numbers greater than 120, the existence of which has been described as “vanishingly small” and whose discovery becomes technically much more difficult. Yet theorists postulate a so-called “island of stability” of superheavy isotopes beyond this range that have stable lifetimes of minutes, hours or even days, and might possess exotic and unusual attributes that may prove useful in applications with advanced materials.
 
For now, the teams credited with discovery of the four new elements will be allowed to propose names for their respective finds, which are currently designated by temporary Latin-based names that reference their atomic numbers – ununtrium, ununpentium, ununseptium, and ununoctium. Each new element may be named after scientists, locations, minerals, attributes of the element, or even mythological references. Of particular note is element 113 (ununtrium), attributed to work from the RIKEN research group from Japan. This element is the first whose discovery is credited to an East Asian research institution, and an historic opportunity exists to represent that continent and culture’s contributions to science with the choice of a permanent name.
 
An IUPAC committee will make the final choice of names and representative atomic symbols based on historic usage, consistency, and translatability. And I bet you’re thinking you know the perfect name for one of those new elements. Unfortunately, the general public will not be part of the naming process.
 
If you’d like to learn more about the new elements, click here to read