americium

[am-uh-rish-ee-uh m] /ˌæm əˈrɪʃ i əm/
noun, Chemistry
1.
a transuranic element, one of the products of high-energy helium bombardment of uranium and plutonium. Symbol: Am; atomic number: 95.
Origin
1945-50, Americanism; Americ(a) + -ium
Examples from the web for americium
  • The primary plutonium decay products are isotopes of uranium, neptunium, and americium.
British Dictionary definitions for americium

americium

/ˌæməˈrɪsɪəm/
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, 243Am: 7.4 × 10³ years; valency: 2,3,4,5, or 6; relative density: 13.67; melting pt: 1176°C; boiling pt: 2607°C (est)
Word Origin
C20: from America (because it was discovered at Berkeley, California) + -ium
americium in Medicine

americium am·er·i·ci·um (ām'ə-rĭsh'ē-əm)
n.
Symbol Am
A white metallic synthetic element of the actinide series; its longest-lived isotopes, Am 241 and Am 243, are used as radiation sources in research. Atomic number 95; specific gravity 13.7; valence 2, 3, 4, 5, 6.

americium in Science
americium
  (ām'ə-rĭsh'ē-əm)   
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.