Scientists from the international overseeing committees of physics and chemistry have added two new elements to the periodic table.
The still-unnamed elements 114 and 116 are both extremely radioactive and, with respective atomic mass unit values of 289 and 292, are now heaviest table-members, taking the place of copernicium and roentgenium.
The discovery of both elements has been credited to the Joint Institute for Nuclear Research in Dubna, Russia and Lawrence Livermore National Laboratory in California. The collaborative parties have proposed the name flerovium for 114, after Soviet scientist Georgy Flyorov, and moscovium for 116, after the region in Russia.
According to Wired:
The two new elements are radioactive and only exist for less than a second before decaying into lighter atoms. Element 116 will quickly decay into 114, and 114 transforms into the slightly lighter copernicium as it sheds its alpha particles.
A joint effort by the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics (IUPAP) required three years to approve the addition. Other periodic table hopefuls 113, 115 and 118 are still pending approval.
The elements are temporarily labeled ununquadium and ununhexium, pending final naming.
A full report of has been published in the journal Pure and Applied Chemistry.