[News] 7th row of Periodic Table completed: 4 new elements added

The seventh row of the periodic table of Chemistry has been completed after four new elements have been added by the scientists. The four new elements have been discovered by scientists in Japan, Russia and America and they are the first ones to be added since 2011 when 114 and 116 were added. According to AP reports, a team of Japanese scientists have met the criteria for naming a new element, the synthetic highly radioactive element 113, more than a dozen years after they began working to create it.

Kosuke Morita, who was leading the research at the government-affiliated Riken Nishina Center for Accelerator-Based Science, was notified of the decision on December 31, 2015 by the US-based International Union of Pure and Applied Chemistry. “Now that we have conclusively demonstrated the existence of element 113, we plan to look to the unchartered territory of element 119 and beyond,” Morita said in a statement.

A joint working group of the IUPAC and International Union of Pure and Applied Physics also announced decisions on recognition of discoveries of elements 115, 117 and 118.

Discoveries of atomic elements have often involved competition between scientists. “To scientists, this is of greater value than an Olympic gold medal,” Ryoji Noyori, former Riken president and Nobel laureate in chemistry told reporters.

Element 113 sits between Copernicium and Flerovium on the periodic table. A joint team of scientists in Russia and the Lawrence Livermore National Laboratory in the US were also pitching for the naming rights for the 113 element, after announcing its discovery in 2004. Isotopes of element 113 have a very short half-life, lasting for less than a thousandth of a second, making its discovery very difficult.

The scientists have continued research for the last seven years to secure a place for elements 113, 115, 117 and 118 on the periodic table. Until now, the four elements manifested only for a very short span of time – about a thousand of one second – making it very difficult for scientists to prove their existence.

The four elements bore temporary names so far. Elements 113, 115, 117 and 118 were being identified by Uut, Uup, Uus and Uuo, respectively.

The periodic table has seen many changes since Russian chemist Dmitri Mendeleev designed it in 1869:

The noble gases including helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) were added to the table between 1895 and 1901. Likewise, additions have made to the periodic table as new elements have been discovered in the last hundred years.

In 1914, English physicist Henry Gwyn-Jeffries Moseley found out that the each atomic nucleus can be assigned a number, according to the number of protons in that atom. This changed the way periodic table worked. The table was redesigned according to the atomic number of elements rather than their atomic weight.