bohrium

Synthesized, radioactive element of the transactinide series, atomic number 107, relative atomic mass 262. It was first synthesized by the Joint Institute for Nuclear Research in Dubna, Russia, in 1976; in 1981 the Laboratory for Heavy-Ion Research in Darmstadt, Germany, confirmed its existence. Until 1997 it was known by the temporary name, unnilseptium. It was named in 1997 after Danish physicist Niels Bohr.

The first chemical study of bohrium was published in 2000, after experiments by Swiss researchers produced six atoms of bohrium-267 (half-life 17 seconds). It behaved like a typical group VII element, with chemical similarities to technetium and rhenium.