Illustration of Americium

1944 Americium

The book of science

Tom Sharp

Berkeley, ChicagoGlenn T. Seaborg, Leon O. Morgan, Ralph A. James, Albert Ghiorso elements Illustration of Americium


Glenn T. Seaborg, Ralph A. James, and Albert Ghiorso bombarded plutonium-239 dioxide with neutrons. They separated americium-241 and americium-242 after dissolving the bombarded plutonium dioxide in acids. Separating curium and americium was so difficult that the team called them pandemonium and delirium.

Atomic number 95

A small dot of americium-241 sealed in gold emits alpha particles into an ionizing chamber in a simple device powered by a nine-volt battery that beeps when smoke enters the chamber.

Stuff in the home

Most of the stuff in our home doesn’t contain class-A radionuclides. Our glacial soils don’t emit radon. We probably suffer rays from outer space ionizing atoms in our digestive tracts, but no industrial source of nuclear carcinogens sits around, or hangs on the ceiling except for the americium-241 in smoke detectors.

Americium, accent on the third syllable, with the “c” pronounced softly as an “s” or “sh,” is bioaccumulative and harmful to life. Americium-241 is fissile and more radioactive than plutonium-239; however, it a small amount of it is an essential component in common smoke detectors.

See also in The book of science:

Readings in wikipedia:

Other readings:

  • Americium,” Elementymology & Elements Multidict, by Peter van der Krogt