Seaborgium
Encyclopedia : S : SE : SEA : Seaborgium
Seaborgium (Eka-Tungsten) is a chemical element in the periodic table that has the symbol Sg and atomic number 106. It was also known as unnilhexium (Unh), and at one time rutherfordium was suggested. Seaborgium is a synthetic element whose most stable isotope 271Sg has a half-life of 2.4 minutes. ([Disputed statementdisputed]—see [
Contents
History
Element 106 was discovered almost simultaneously by two different laboratories. In June
1974, an
American research team led by
Albert Ghiorso at the
Lawrence Radiation Laboratory at the
University of California, Berkeley reported creating an isotope with mass number 263 and a half-life of 1.0 s, and in September
1974, a
Soviet team led by
G. N. Flerov at the
Joint Institute for Nuclear Research at
Dubna reported producing an isotope with mass number 259 and a half-life of 0.48
s,
Because their work was independently confirmed first, the Americans suggested the name seaborgium to honor the American chemist Glenn T. Seaborg, who is sometimes credited as a member of the American team along with Ghiorso, J.M. Nitschke, J.R. Alonso, C.T. Alonso, M. Nurmia, E. Kenneth Hulet, and R.W. Lougheed. The name selected by the team became controversial. An international committee decided in 1992 that the Berkeley and Dubna laboratories should share credit for the discovery.
An element naming controversy erupted and as a result IUPAC adopted unnilhexium (symbol Unh) as a temporary, systematic element name. In 1994 a committee of IUPAC recommended that element 106 be named rutherfordium and adopted a rule that no element can be named after a living person. This ruling was fiercely objected to by the American Chemical Society. Critics pointed out that a precedent had been set in the naming of einsteinium during Albert Einstein's life. In 1997, as part of a compromise involving elements 104 to 108, the name seaborgium for element 106 was recognized internationally.
Isotopes
There are 11 known isotopes of Seaborgium, the longest-lived isotope is
269Sg which decays through
alpha decay and
spontaneous fission. It has a half-life of 22 s.
([Disputed statementdisputed]—see [ms.
References
External links
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.