Berkelium is a transuranic radioactive chemical element named after the city of Berkeley, California.
Core Principles & Analysis
Berkelium was synthesized in December 1949 by Thompson, Ghiorso, and Seaborg via alpha bombardment of americium-241; its name honors Berkeley, echoing how terbium was named after Ytterby.
Its most stable isotope, berkelium-247, has a half-life of about 1,380 years, but the reactor-made isotope berkelium-249 decays with a half-life of only 330 days.
A 22-milligram berkelium-249 target produced at Oak Ridge's High Flux Isotope Reactor enabled the 2010 discovery of element 117, tennessine, essentially the element's only large-scale application.