americium

noun Chemistry.

1. a transuranic element, one of the products of high-energy helium bombardment of uranium and plutonium. Symbol: Am; atomic number: 95.

noun

1. a white metallic transuranic element artificially produced from plutonium. It is used as an alpha-particle source. Symbol: Am; atomic no: 95; half-life of most stable isotope, 243 Am: 7.4 × 10³ years; valency: 2,3,4,5, or 6; relative density: 13.67; melting pt: 1176°C; boiling pt: 2607°C (est)

n. Symbol Am

1. A white metallic synthetic element of the actinide series whose longest-lived isotopes, Am 241 and Am 243, are used as radiation sources for bone mineral analysis and in treating cancer. Atomic number 95.

1. Symbol Am A synthetic, silvery-white, radioactive metallic element of the actinide series that is produced artificially by bombarding plutonium with neutrons. Americium is used as a source of alpha particles for smoke detectors and gamma rays for industrial gauges. Its most stable isotope has a half-life of 7,950 years. Atomic number 95; specific gravity 11.7; valence 3, 4, 5, 6. See Periodic Table.