Nihonium

Nihonium is a synthetic, radioactive chemical element with the symbol Nh and atomic number 113. It has no stable isotopes and has been produced only in laboratories. The element was first synthesized in 2004 by a team at RIKEN in Japan, who bombarded a bismuth-209 target with zinc-70 ions; subsequent decay chains confirmed the creation of element 113.

In 2016, IUPAC adopted the name nihonium for element 113, derived from Nihon, the Japanese word for Japan, and the traditional name for the country. The symbol Nh was confirmed; previously the element was referred to by the temporary systematic name ununtrium (Uut).

Nihonium lies in period 7 and group 13 of the periodic table. It is expected to be a metal, with properties influenced by relativistic effects characteristic of transactinide elements. All known isotopes decay via alpha decay or spontaneous fission, and half-lives range from milliseconds to a few seconds for the most stable forms.

Because of its short half-life and limited production, nihonium has not been studied in detail chemically. Predictions suggest it may exhibit a +1 oxidation state as a heavy member of group 13, but its chemistry remains largely uncharacterized. It has no practical applications and is of interest primarily for basic scientific research.