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

More recently, Cotruvo and his colleagues found in the lab that lanmodulin binds tightly and readily to americium and curium—and prefers them to many of its regular dance partners.

From Scientific American • Dec. 28, 2021

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

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

From BBC • Mar. 6, 2014

The workers inhaled plutonium and americium, which if lodged in the body bombards internal organs with subatomic particles for the rest of the person’s lifetime.

From New York Times • Feb. 28, 2014