A chemical element, symbol Bh, atomic number 107. Bohrium was synthesized and identified in 1981 by using the Universal Linear Accelerator (UNILAC) of the Gesellschaft für Schwerionenforschung (GSI) at Darmstadt, West Germany, by a team led by P. Armbruster and G. Müzenberg. The reaction used to produce the element was proposed and applied in 1976 by Y. T. Oganessian and colleagues at Dubna Laboratories in Russia. A ²⁰⁹Bi target was bombarded by a beam of ⁵⁴Cr projectiles.