Nihonium is a synthetic chemical element with symbol Nh and atomic number 113. It is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide element at the intersection of period 7 and group 13. Its creation was reported in 2003 by a Russian–American collaboration at the Joint Institute for Nuclear Research in Dubna, Russia, and in 2004 by a team of Japanese scientists at Riken in Wakō, Japan. The discoveries were confirmed by independent teams working in the United States, Germany, Sweden, and China. In 2015 the element was officially recognised by the IUPAC/IUPAP Joint Working Party; naming rights were assigned to Riken, as they were judged to have been first to confirm their discovery. The name, approved in the same year (announcement pictured), derives from a Japanese word for Japan, Nihon. Few details are known about nihonium, as it has only been formed in very small amounts that decay away within seconds. (Full article...)