On Nov. 28 2016, the International Union of Pure and Applied Chemistry (IUPAC) reported that it had approved the names and symbols for four elements: nihonium (Nh), moscovium (Mc), tennessine (Ts) and oganesson (Og) respectively for elements 113, 115, 117, and 118. The four new elements means that the seventh period of the periodic table of elements is now complete.

In keeping with tradition, the newly discovered elements have been named after a place, geographical region or a scientist. The ending of the names also reflects and maintains historical and chemical consistency: “-ium” for elements 113 and 115 and as for all new elements of groups 1 to 16; “-ine” for element 117 and belonging to group 17 and “-on” for element 118 element belonging to group 18. The recommendations will be published in the IUPAC journal Pure and Applied Chemistry.

The name nihonium with the symbol Nh for element 113 was proposed by the discoverers at RIKEN Nishina Center for Accelerator-Based Science in Japan. The name came from Nihon, which is one of the two ways to say “Japan” in Japanese and means “the Land of the Rising Sun.” Moscovium with the symbol Mc for element 115 and tennessine with the symbol Ts for element 117 were proposed by the discoverers at the Joint Institute for Nuclear Research, Dubna in Russia and the American institutions Oak Ridge National Laboratory, Vanderbilt University and Lawrence Livermore National Laboratory.

Moscovium, in recognition of the Moscow region, honours the ancient Russian land that is the home of the Joint Institute for Nuclear Research where the discovery experiments were conducted using the Dubna Gas-Filled Recoil Separator in combination with the heavy ion accelerator capabilities of the Flerov Laboratory of Nuclear Reactions. Tennessine is in recognition of the contribution of the Tennessee region of the United States, including the University of Tennessee at Knoxville, to superheavy element research.

Lastly, and in line with the tradition of honouring a scientist, the name oganesson and symbol Og for element 118 was proposed by the collaborating teams of discoverers at the Joint Institute for Nuclear Research, Dubna and Lawrence Livermore National Laboratory. The name honours 83-year-old professor Yuri Oganessian’s pioneering contributions to transactinoid elements research. Oganessian’s many achievements include the discovery of superheavy elements and significant advances in the nuclear physics of superheavy nuclei including experimental evidence for the “island of stability.”

The exploration of new elements continues and scientists are searching for elements beyond the seventh row of the periodic table.  IUPAC and the International Union of Pure and Applied Physics (IUPAP) are establishing a new joint working group whose task will be to examine the criteria used to verify claims for the discovery of new elements.