Seaborgium

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Seaborgium ( " eka- tungsten ") is an exclusively artificially produced chemical element with the chemical symbol Sg and atomic number 106, it is one of the Transactinoiden (7th period d-block ). All seaborgium isotopes are radioactive. It was first produced in 1974, about the same time at the Nuclear Research Dubna ( USSR ) and the University of California, Berkeley.

After it was initially the name Unnilhexium (symbol Unh ), it was in 1997 after the Elementnamensgebungskontroverse the current name, which was given to him in honor of the American chemist Glenn T. Seaborg. Seaborgium is the only element that was named after a scientist nor during his lifetime. Glenn T. Seaborg died on 25 February 1999.

History

The synthesis of element 106 succeeded in June 1974 Soviet scientists led by GN Flerov and Yuri Ts Oganessian at the nuclear research center in Dubna. With a heavy-ion accelerator, a chromium ion beam with an intensity of 200 billion particles per second and an ion energy of 280 MeV was aimed at a target material is lead different mass number. It could be demonstrated the formation of nuclei, their spontaneous decay could be assigned to the element 106. This study, however, was not considered a significant indication of the element 106.

Three months later, in September 1974 and American scientists from the research group led by Albert Ghiorso and Glenn T. Seaborg announced the success of their efforts. They bombarded californium with oxygen nuclei:

Neither the Soviet nor the American scientists a name was suggested in the following years, because in the meantime you was obviously tired of the "name of war " continue. Only in recent times seaborgium was proposed; a naming that has not yet been definitively laid down by IUPAC.

Properties

Seaborgium is an artificially produced radioactive element of the seventh period, the sub-group 6 can be assigned, in the tungsten is the next lightest element. It has the relative atomic mass of 263.1182. Through its properties, little is known, since it decays within a short time and are difficult to investigate is. It is estimated that the melting point is 2800 ° C Seaborgium and the boiling point 6500 ° C.

Isotopes

Meanwhile, six isotopes are synthesized, all of which are very short-lived: 259Sg (0.48 s ), 260SG (3.6 ms), 261Sg (0.23 s ), 263 Sg ( 0.9 s ), 265Sg ( 2 - 30 s) and 266Sg (10-30 s ).

Use

The item was produced exclusively for research purposes and also has no meaning.

Safety

Classifications according to the Hazardous Substances Ordinance are not available because they only include the chemical danger and play a very minor role compared to the risks based on the radioactivity. Even the latter applies only when there is a relevant matter for that amount.