hassium

hassium hăs´ēəm, häs´– [key], artificially produced radioactive chemical element symbol Hs at. no. 108 mass number of most stable isotope 277 m.p., b.p., sp. gr., and valence unknown. Situated in Group 8 of the periodic table , it is expected to have properties similar to those of osmium .

In 1984 a German research team led by P. Armbruster and G. Münzenberg at the Institute for Heavy Ion Research at Darmstadt bombarded lead-208 atoms with iron-58 ions. In 10 days of bombardment, they successfully produced three atoms of an isotope of element 108 with mass number 265 and a half-life of only 2 msec. They suggested that the new element be named hassium, which is derived from the Latin name for the German state of Hesse , where the institute is located. 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 108 be named hahnium. The name hassium was adopted internationally, however, in 1997. The most stable isotope of hassium, hassium-277, has a half-life of approximately 11 min.

See also synthetic elements transuranium elements .

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

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The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.