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Seaborgium


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Proposed Name

Atomic Number:106Atomic Symbol:Sg
Atomic Weight:263Electron Configuration:2-8-18-32-12-2
Shells:2,8,18,32,32,12,2Filling Orbital:6d4
Melting Point:700oCBoiling Point:1737oC
Description:Man made radioactive metal.


History

In June 1974, members of the Joint Institute for Nuclear Research in Dubna, U.S.S.R., reported their discovery of Element 106, which they reported to have synthesized. In September 1974, workers of the Lawrence Berkeley and Livermore Laboratories also claimed creation Element 106 "without any scientific doubt." The LBL and LLL Group used the Super HILAC to accelerate 18O ions onto a 249Cf target.

Elements

Element 106 was created by the reaction 249Cf(18O, 4N)263X, which decayed by alpha emission to rutherfordium, and then by alpha emission to nobelium, which in turn further decayed by alpha between daughter and granddaughter. The element so identified had alpha energies of 9.06 and 9.25 MeV with a half-life of 0.9 +/- 0.2 s.

Uses

At Dubna, 280-MeV ions of 54Cr from the 310-cm cyclotron were used to strike targets of 206Pb, 207Pb, and 208Pb, in separate runs. Foils exposed to a rotating target disc were used to detect spontaneous fission activities. The foils were etched and examined microscopically to detect the number of fission tracks and the half-life of the fission activity.

Other experiments were made to aid in confirmation of the discovery. Neither the Dubna team nore the Berkeley-Livermore Group has proposed a name as yet for element 106 (unnilhexium).


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