Moscovium

Moscovium is element 115. A Russian–American team at the Joint Institute for Nuclear Research in Dubna, working with Lawrence Livermore National Laboratory, made it in 2003 by firing calcium-48 nuclei at americium. It was named in 2016 after the Moscow region, where Dubna lies.

Like all superheavy elements, it is made by fusing two lighter nuclei, an event so rare that atoms appear one at a time. Moscovium atoms decay in less than a second, usually by shooting out an alpha particle and becoming nihonium. Its place below bismuth suggests it would be a heavy metal, but its chemistry has hardly been studied.