In 1976 a Soviet team led by Y. Oganessian at the Joint Institute for Nuclear Research at Dubna bombarded bismuth-209 atoms with chromium-54 ions to produce an isotope with mass number 261 and a half-life of 1–2 msec. In 1981 a German research team led by P. Armbruster and G. Münzenberg at the Institute for Heavy Ion Research at Darmstadt also bombarded bismuth-209 atoms with chromium-54 ions. By reducing the temperature of the target atoms, the Germans were able to produce and unambiguously identify an isotope of element 107 having mass number 262 and a half-life of 5 msec. The Germans suggested the name nielsbohrium, which the Soviets had suggested be given to element 105 (dubnium), to honor the Danish physicist Niels Bohr.
In 1994 a committee of the International Union of Pure and Applied Chemistry (IUPAC), convened to resolve naming disputes for the transactinide elements, recommended that element 107 be named bohrium. While this conforms to the names of other elements honoring individuals, where only the surname is taken, it was opposed by many who were concerned that it could be confused with boron, the name for element 5. In 1997, however, the name bohrium for element 107 was recognized internationally.
See also synthetic elements; transuranium elements.
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Periodic Table of the Elements: BohriumAtomic Number:107Atomic Symbol:BhBohriumAtomic Weight:(262)ElectronConfiguration:2 · 8 · 1832 · 3213 · 2
Bh, symbol for the element bohrium.
Ns, formerly the suggested symbol for the name nielsbohrium, which was applied variously to two elements, now called bohrium and dubnium.
Nielsbohrium, symbol Ns, former suggested name for both element 105, now called dubnium, and element 107, now called bohrium.
Transuranium elements, in chemistry, radioactive elements with atomic numbers greater than that of uranium (at. no. 92). All the transuranium elements of the actinide series were discovered as...
ElementsElementSymbolAtomic NumberAtomic Weight1Melting Point(Degrees Celsius)Boiling Point(Degrees Celsius)1 Parentheses indicate most stable isotope.actiniumAc89227.02781050.3200....
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