berkelium

Berkelium is a synthetic chemical element with the symbol Bk and atomic number 97. It is a member of the actinide series. Berkelium was first synthesized in 1949 by Glenn T. Seaborg, Albert Ghiorso, and Stanley G. Thompson at the University of California, Berkeley, and it was named after the city of Berkeley, California, where the discovery took place.

Physically, berkelium is a radioactive metal and, like other heavy actinides, is typically described as silvery and prone to tarnishing in air. In chemistry, berkelium most commonly exhibits the +3 oxidation state and can form compounds such as berkelium(III) oxide (Bk2O3) and berkelium(III) fluoride. Higher oxidation states are less common and short-lived in solution. Berkelium metals and compounds are produced only in very small quantities and require specialized facilities.

Isotopes and production are limited by radioactivity and scarcity. All isotopes of berkelium are radioactive. Dozens have been synthesized; the known isotopes have half-lives ranging from hours to years. Berkelium is produced artificially in nuclear reactors or particle accelerators by irradiating lighter actinides, and it is typically recovered in trace amounts from irradiated targets.

Uses and applications are primarily scientific. Because of its rarity and radioactivity, berkelium has no significant commercial uses. It is employed mainly in fundamental research, such as studying the properties of heavy actinides and as a target material for producing heavier elements.

Safety and handling require specialized facilities and trained personnel due to intense radioactivity and chemical toxicity.