americium

American  

[am-uh-rish-ee-uhm] / ˌæm əˈrɪʃ i əm /

noun

Chemistry.

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

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americium British  

/ 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, 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)

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americium Scientific  

/ ăm′ə-rĭsh′ē-əm /

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.

2. See Periodic Table

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Etymology

Origin of americium

An Americanism dating back to 1945–50; Americ(a) + -ium

Example Sentences

See Examples For:

americium

In Colorado, for instance, 27 buildings house scary-sounding elements such as cesium 137, cobalt 60, americium 241 and iridium 192.

From Scientific American ● Mar. 11, 2022

Spent fuel rods contain a variety of products, consisting of unstable nuclei ranging in atomic number from 25 to 60, some transuranium elements, including plutonium and americium, and unreacted uranium isotopes.

From Textbooks ● Feb. 14, 2019

Inhalation of the particles, which included uranium, thorium, plutonium and americium, can increase the risk of cancer.

From Seattle Times ● Jun. 14, 2018

Power would come from a tiny radioactive source like americium, the element in smoke detectors.

From New York Times ● Apr. 12, 2016

More tests confirmed that two radioactive particles, isotopes of americium and plutonium, were found on aboveground air filters.

From BBC ● Mar. 6, 2014