bohrium (Bh), a synthetic element in Group VIIb of the periodic table. It is thought to be chemically similar to the rare metal rhenium.
In 1976 Soviet scientists at the Joint Institute for Nuclear Research in Dubna, Russia, U.S.S.R., announced that they had synthesized element 107, later given the official name bohrium, by bombarding a target of bismuth-209 with ions of chromium-54. The resultant collisions were reported to have produced an isotope of the element with a mass number of 261 and a half-life of 1–2 milliseconds. The existence of the element was confirmed by West German physicists at the Institute for Heavy Ion Research (Gesellschaft für Schwerionenforschung [GSI]) in Darmstadt.