On Mar. 29, 1999, the American Chemical Society announced that the 2000 Priestley Medal was to be awarded to Darleane C. Hoffman “to recognize distinguished services to chemistry.”

Dr. Hoffman gained international recognition for capturing and analyzing elusive transuranic elements (elements heavier than uranium) that typically exist for only short periods, making important discoveries about the nature of fission—the atomic process at the heart of nuclear power.