A white metallic transuranic section of the actinide series, having isotopes with mass numbers from 237 to 246 and half-lives from 25 mins to 7,950 many years. Its longest-lived isotopes, in the morning 241 and Am 243, are alpha-ray emitters made use of as radiation sources in research. Atomic number 95; specific gravity 11.7; valence 3, 4, 5, 6. See dining table at factor.
The substance factor (logo Am) with an atomic quantity of 95.
a radioactive transuranic metallic element; discovered by bombarding uranium with helium atoms