Americium
For crystal research.
Atomic Number: 95
Atomic Symbol: Am
Atomic Weight: 243
Electron Configuration:[Rn]7s^2 5f^7History
(the Americas) Americium was the fourth transuranic element to be discovered; the isotope
241Am was identified by Seaborg, James, Morgan, and Ghiorso late in 1944 at the wartime
Metallurgical Laboratory of the University of Chicago as the result of successive neutron capture
reactions by plutonium isotopes in a nuclear reactor. The luster of freshly prepared americium
metal is white and more silvery than plutonium or neptunium prepared in the same manner. It
appears to be more malleable than uranium or neptunium and tarnishes slowly in dry air at
room temperature. Americium must be handled with great care to avoid personal
contamination. The alpha activity from 241Am is about three times that of radium. When gram
quantities of 241Am are handled, the intense gamma activity makes exposure a serious problem.
241Am has been used as a portable source for gamma radiography. It has also been used as a
radioactive glass thickness gauge for the flat glass industry and as a source of ionization for
smoke detectors.
Isotope
Sources: CRC Handbook of Chemistry and Physics and the American Chemical Society.
Last Updated: 12/19/97, CST Information Services Team
Americiumhttp://pearl1.lanl.gov/periodic/elements/95.html [5/10/2001 3:09:04 PM]