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Sg - Seaborgium

Seaborgium

 Seaborgium 
Sg
Atomic Number: 106
Atomic Weight: -263.0
Element Type: Transition Metal
Crystal Structure:
Melting Point: °C = °F = K
Boiling Point: °C = °F = K
Critical Temp: °C = °F = K
Atomic Radius: Å (Å = Angstrom = 10-10 m)
Covalent Radius: Å
Electronegativity:

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. GlennSeaborg was part of this group, and the element was named in his honor. Seaborgium isoften still referred to as Element 106 because the international committee in charge ofnames changed the rules. They decided retroactively it couldn't be named after a livingperson.

In September 1974, workers of the Lawrence Berkeley and Livermore Laboratories alsoclaimed creation Element 106 "without any scientific doubt." The LBL and LLLGroup used the Super HILAC to accelerate 18O ions onto a 249Cf target.

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

At Dubna, 280-MeV ions of 54Cr from the 310-cm cyclotron were used to strike targets of206Pb, 207Pb, and 208Pb, in separate runs. Foils exposed to a rotating target disc wereused to detect spontaneous fission activities. The foils were etched and examinedmicroscopically to detect the number of fission tracks and the half-life of the fissionactivity.

Other experiments were made to aid in confirmation of the discovery. Neither the Dubnateam nor the Berkeley-Livermore Group has proposed a name as of yet for element 106(unnilhexium).


Sources


Science Quote

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Albert Einstein
(1879-1955)


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