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106 dubnium ← seaborgium → bohrium W ↑ Sg ↓ (Uph) Periodic Table - Extended Periodic Table
General
Name, Symbol, Number	seaborgium, Sg, 106
Chemical series	transition metals
Group, Period, Block	6, 7, d
Appearance	unknown, probably silvery white or metallic gray
Standard atomic weight	(263)  g·mol−1
Electron configuration	perhaps [Rn] 7s2 5f14 6d4 (guess based on tungsten)
Electrons per shell	2, 8, 18, 32, 32, 12, 2
Physical properties
Phase	presumably a solid
Density (near r.t.)	35 (est.)  g·cm−3
Atomic properties
Crystal structure	cubic body centered
Oxidation states	6, 5, 4, 3, 2, 1, −1 (mildly acidic oxide)
Atomic radius (calc.)	132  pm
Covalent radius	63 (calc.) pm
Miscellaneous
CAS registry number	54038-81-2
Selected isotopes
Main article: Isotopes of seaborgium iso NA half-life DM DE (MeV) DP 271Sg syn 2.4 min α SF
References

Seaborgium (pronounced /siːˈbɔrgiəm/), also called eka-tungsten, is a chemical element in the periodic table that has the symbol Sg and atomic number 106. Seaborgium is a synthetic element whose most stable isotope ²⁷¹Sg has a half-life of 2.4 minutes. Its chemistry probably resembles that of tungsten.

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 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 in recognition of his participation in the discovery of several other actinides. 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 (pronounced /ˌjuːnɪlˈhɛksiəm/, 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.

Main article: Isotopes of seaborgium

There are 12 known isotopes of Seaborgium, the longest-lived of which is ²⁷¹Sg which decays through alpha decay and spontaneous fission. It has a half-life of 2.4 minutes. The shortest-lived isotope is ²⁵⁸Sg which also decays through alpha decay and spontaneous fission. It has a half-life of 2.9 ms.

• Los Alamos National Laboratory - Seaborgium
• National Nuclear Data Center, Brookhaven National Laboratory. Information extracted from the NuDat 2.1 database (retrieved Sept. 2006).

Wikimedia Commons has media related to:

Seaborgium

• WebElements.com - Seaborgium