The International Union of Pure and Applied Chemistry (IUPAC) has ratified four new elements to be officially added to the periodic table. The newly accepted names will be for elements 113, 115, 117 and 118. As of 2016, these new elements will be known as Nihonium, Moscovium, Tennesine and Oganesson. These new additions mean that the seventh row of the periodic table is now complete.
The elements were first synthesised between 2002 and 2010 and were temporarily named ununtrium, ununpentium, ununseptium, and ununoctium. By December 2015, IUPAC recognised their discovery and allowed the teams involved to suggest names. As IUPAC have recently updated their guidelines for the naming of newly discovered elements, the teams were limited to – a mythological concept or character, a mineral or similar substance, a place or geographical region, a property of the element or a scientist.
- Nihonium (Nh) was first discovered by a team of Japanese scientists at the Riken Centre for Accelerator-Based Science in Japan. The name proposed by the researchers was based on the Japanese word ‘Nihon’ which means Japan.
- Moscovium (Mc) and Tennesine (Ts) were first produced by a collaboration of Russian and American scientists and so the names they proposed were based on the city of Moscow and the state of Tennessee. Finally Oganesson
- (Og) was named after Yuri Oganessian. Yuri Oganessian is widely considered to be the world’s leading researcher in super heavy metals, having previously discovered Flerovium. He is presently researching into the island of stability. Prior to the naming of Oganesson the only element named after a living person was Seaborgium named for Glenn Seaborg.
The next elements along the periodic table, 119 and 120, are the lightest elements to have not yet been discovered. They have proven to be exceptionally difficult to synthesise despite many attempts by German and Russian teams. It has been suggested that these elements, with the current temporary names of ununennium and unbinilium, could be the last to be discovered on the periodic table. These elements are pushing the boundaries of current technology, as their half-lives are so short that they are thought to decay before reaching the detectors.
Although there is hope that further super heavy elements may be discovered within the theoretical ‘island of stability’. Islands of stability are a group of super heavy elements with the potential to have longer half-lives, in the order of several minutes, than their place on the periodic table would suggest. This is due to these elements having ‘magic numbers’ of protons and neutrons.
The hypothesis is that the atomic nucleus is comprised of shells and that, similar to electron shells, these shells are groups quantum energy levels. So once the number of protons and neutrons fills an energy shell, the element will have a much more stable nucleus and thus will have a longer half life than nearby isotopes with unfilled shells.
While islands of stability may provide future avenues of research, the possibility remains that these four newly named elements could be the last able to be discovered with current technology.