In December 2015, elements 113, 115, 117, and 118 were approved by the International Union of Pure and Applied Chemistry (IUPAC) to be added to the periodic table. Five months later, they have names, and are to be added to the table as seventh-period elements. These elements are extremely heavy, and very unstable due to their high number of protons. Their names are as follows:
- Element 113: nihonium (Nh)
- Element 115: moscovium (Mc)
- Element 117: tennessine (Ts)
- Element 118: oganesson (Og)
They are named after the areas where they were invented. Nihonium's name comes from Nihon, which means Japan in Japanese. The last time it was created was in 2012 by Japanese scientists at the RIKEN Nishina Center for Accelerator by colliding zinc nuclei in a thin layer of bismuth. Nihonium's most stable isotope has a half life of 20 seconds.
Moscovium is named after Moscow, since it was created at the Joint Institute for Nuclear Research in Dubna, Russia. Element 117 is named tennessine because it was created at Oak Ridge National Laboratories in Tennessee. Element 118 is named after physicist Yuri Oganessian.
