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| Atomic Number: | 95 |
| Atomic Radius: | 184 pm |
| Atomic Symbol: | Am |
| Melting Point: | 1176 șC |
| Atomic Weight: | 243 |
| Boiling Point: | 2011 șC |
| Electron Configuration: | [Rn]7s25f7 |
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History
(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 at the University of Chicago as the result of successive
neutron capture reactions by plutonium isotopes in a nuclear reactor.
Properties
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.
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