bohrium [bôr′ē əm]n.a radioactive chemical element with a very short half-life: a transactinide produced by bombarding bismuth with high-energy nuclear particles: symbol, Bh; at. no., 107: see the periodic table of elements in the Reference Supplement
* * *bohr·i·um (bôrʹē-əm, bōrʹ-) n. Symbol BhAn artificially produced radioactive element with atomic number 107 whose most long-lived isotopes have mass numbers of 261, 262, and 264 with half-lives of 11.8 milliseconds, 0.1 seconds, and 0.44 seconds, respectively. Also called unnilseptium. See table at element.[After Bohr, Niels Henrik David.]
* * *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.
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