Americium is a synthetic radioactive element created by bombarding plutonium with neutrons.
Core Principles & Analysis
Americium was synthesized in 1944 by Glenn Seaborg's group at the wartime Metallurgical Laboratory in Chicago and named for the Americas, paralleling its lanthanide analog europium.
Seaborg first revealed americium's existence on the children's radio quiz show 'Quiz Kids' in November 1945, days before the formal scientific announcement.
Americium-241, with a 432-year half-life, is the alpha source in ionization smoke detectors, placing about a third of a microgram of a synthetic element in millions of homes.