Born Apr. 19, 1912, in Ishpeming, Mich. American physicist.

Seaborg graduated from the University of California at Los Angeles in 1934. After receiving the Ph.D. degree from the University of California at Berkeley in 1937, he joined the university’s research staff. He was appointed a professor there in 1945 and was chancellor from 1958 until 1961. Between 1942 and 1946, Seaborg worked on the industrial production of plutonium at the metallurgical laboratory of the University of Chicago. From 1954 to 1961 he was associate director of the Radiation Laboratory at Berkeley; he returned to this position in 1971. Between 1961 and 1971 he was chairman of the US Atomic Energy Commission.

Together with E. McMillan, Seaborg synthesized plutonium in 1940–41. With other scientists, he discovered americium (1944–45), curium (1944), berkelium (1949), californium (1950), einsteinium (1952), fermium (1953), and mendelevium (1955). In subsequent years, he worked on the synthesis of even heavier elements.

Seaborg received a Nobel Prize in 1951 with McMillan. He became a foreign member of the Academy of Sciences of the USSR in l971.