Seaborgium

1970

It is one of only two elements named after a living person at the time of naming, the other being oganesson, element 118. ==Introduction== ==History== Following claims of the observation of elements 104 and 105 in 1970 by Albert Ghiorso et al.

1971

This reaction was tried again several years later, in 1974, and the Berkeley team realized that their new data agreed with their 1971 data, to the astonishment of Ghiorso.

Hence, element 106 could have actually been discovered in 1971 if the original data was analyzed more carefully. Two groups claimed discovery of the element.

1972

In 1972, the HILAC accelerator received equipment upgrades, preventing the team from repeating the experiment, and data analysis was not done during the shutdown.

1974

The chemical properties of seaborgium are characterized only partly, but they compare well with the chemistry of the other group 6 elements. In 1974, a few atoms of seaborgium were produced in laboratories in the Soviet Union and in the United States.

This reaction was tried again several years later, in 1974, and the Berkeley team realized that their new data agreed with their 1971 data, to the astonishment of Ghiorso.

Unambiguous evidence of element 106 was first reported in 1974 by a Russian research team in Dubna led by Yuri Oganessian, in which targets of lead-208 and lead-207 were bombarded with accelerated ions of chromium-54.

The isotope in question was first suggested to be seaborgium-259, but was later corrected to seaborgium-260. + → + 2 + → + A few months later in 1974, researchers including Glenn T.

1992

The dispute on discovery, however, dragged on until 1992, when the IUPAC/IUPAP Transfermium Working Group (TWG), formed to put an end to the controversy by making conclusions regarding discovery claims for elements 101 to 112, concluded that the Soviet synthesis of seaborgium-260 was not convincing enough, "lacking as it is in yield curves and angular selection results", whereas the American synthesis of seaborgium-263 was convincing due to its being firmly anchored to known daughter nuclei.

1993

As such, the TWG recognised the Berkeley team as official discoverers in their 1993 report. Seaborg had previously suggested to the TWG that if Berkeley was recognised as the official discoverer of elements 104 and 105, they might propose the name kurchatovium (symbol Kt) for element 106 to honour the Dubna team, which had proposed this name for element 104 after Igor Kurchatov, the former head of the Soviet nuclear research programme.

1994

After being recognized as official discoverers, the Berkeley team started deciding on a name in earnest: Seaborg's son Eric remembered the naming process as follows: The name seaborgium and symbol Sg were announced at the 207th national meeting of the American Chemical Society in March 1994 by Kenneth Hulet, one of the co-discovers.

However, IUPAC resolved in August 1994 that an element could not be named after a living person, and Seaborg was still alive at the time.

1995

And, of course, we didn't infringe on that at all." However, Seaborg responded: Bowing to public pressure, IUPAC proposed a different compromise in August 1995, in which the name seaborgium was reinstated for element 106 in exchange for the removal of all but one of the other American proposals, which met an even worse response.

1997

The priority of the discovery and therefore the naming of the element was disputed between Soviet and American scientists, and it was not until 1997 that the International Union of Pure and Applied Chemistry (IUPAC) established seaborgium as the official name for the element.

Finally, IUPAC rescinded these previous compromises and made a final, new recommendation in August 1997, in which the American and German proposals for elements 104 to 109 were all adopted, including seaborgium for element 106, with the single exception of element 105, named dubnium to recognise the contributions of the Dubna team to the experimental procedures of transactinide synthesis.

1999

This list was finally accepted by the American Chemical Society, which wrote: Seaborg commented regarding the naming: Seaborg died a year and a half later, on 25 February 1999, at the age of 86. ==Isotopes== Superheavy elements such as seaborgium are produced by bombarding lighter elements in particle accelerators that induces fusion reactions.




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