Seaborgium

Seaborgium is a synthetic chemical element, represented by the symbol Sg and carrying the atomic number 106. Its name honors American nuclear chemist Glenn T. Seaborg. Because it is synthetic, seaborgium does not occur naturally and must be produced in a laboratory; it is also radioactive, and its most stable known isotopes have half-lives of only a few minutes. On the periodic table, seaborgium sits in the d-block as a transactinide element. It falls in period 7 and belongs to group 6, making it the fourth member of the 6d series of transition metals. Only a handful of its chemical reactions have been studied, since researchers can produce just a few atoms at a time, and those atoms decay rapidly. A small number of inorganic compounds and one carbonyl, thought to be Sg(CO)6, have been synthesized. These experiments confirm that seaborgium behaves as a heavier version of tungsten within group 6. In 1974, a few atoms of seaborgium were created in laboratories in both the Soviet Union and the United States. The priority of the discovery—and thus the naming rights—was disputed between Soviet and American scientists. It was not until 1997 that the International Union of Pure and Applied Chemistry (IUPAC) settled on seaborgium as the official name. This element is one of only two named after a person who was still alive at the time of naming; the other is oganesson, element 118. After claims of observing elements 104 and 105 in 1970 by Albert Ghiorso and colleagues at the Lawrence Livermore National Laboratory, the team searched for element 106 using oxygen-18 projectiles and a californium-249 target. They reported several alpha decays at 9.1 MeV, now thought to have come from element 106, though this was not confirmed at the time. In 1972, upgrades to the HILAC accelerator prevented the team from repeating the experiment, and data analysis was not carried out during the shutdown. When the reaction was tried again in 1974, the Berkeley team realized their new data matched their 1971 data, surprising Ghiorso. Thus, element 106 could have been discovered in 1971 if the original data had been analyzed more carefully. Two groups claimed discovery. Evidence of element 106 was first reported in 1974 by a Russian team in Dubna led by Yuri Oganessian.