Encyclopedia > Unnilhexium

  Article Content


Redirected from Unnilhexium

Known properties
Name, Symbol, NumberSeaborgium, Sb, 106
Chemical series Transition metals
Group, Period, Block15, 5 , d
Appearance unknown; probably metallic,
silvery white or gray
Atomic weight [266] amu
Electron configuration probably [Rn]5f14 6d4 7s2
e- 's per energy level2, 8, 18, 32, 32, 12, 2
State of matter Presumably a solid
Seaborgium 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 266Sg has a half-life of 30 seconds.

History Element 106 was discovered almost simultaneously by two different laboratories. In June 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 7ms, and in September 1974, an American research team led by A. 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 0.9s. Because their work was independently confirmed first, the Americans suggested the name seaborgium to honor the American chemist Glenn T. Seaborg. This name was extremely controversial because Seaborg was alive. 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 name for this element. 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[?]. In 1997, as part of a compromise involving elements 104 to 108 the name seaborgium for element 106 was recognized internationally.

External links

All Wikipedia text is available under the terms of the GNU Free Documentation License

  Search Encyclopedia

Search over one million articles, find something about almost anything!
  Featured Article
Current Royal Navy ships

... complete and correct as of early 2003. Table of contents 1 Aircraft Carriers 2 Amphibious Assault Ship 3 Type 42 Destroyers[?] 4 Type 23 frigates 5 ...