Seaborgium is a synthetic element with symbol Sg and atomic number 106. Its most stable isotope 271Sg has a half-life of 1.9 minutes. A more recently discovered isotope 269Sg has a potentially slightly longer half-life (ca. 2.1 min) based on the observation of a single decay.
 Chemistry experiments with seaborgium have firmly placed it in group 6 as a heavier homologue to tungsten. Seaborgium is named after Glenn T. Seaborg who was alive at the time the naming was publicized.
Seaborgium belongs to the family of
transuranium elements. The element was the first to be named after a living person.