'americium' definitions:
Definition of 'americium'
From: WordNet
noun
A radioactive transuranic metallic element; discovered by bombarding uranium with helium atoms [syn: americium, Am, atomic number 95]
Definition of 'americium'
From: Elements
- Symbol: Am
- Atomic number: 95
- Atomic weight: (243)
- Radioactive metallic transuranic element, belongs to the actinoids. Ten known isotopes. Am-243 is the most stable isotope, with a half-life of 7.95*10^3 years. Discovered by Glenn T. Seaborg and associates in 1945, it was obtained by bombarding uranium-238 with alpha particles.