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

There are already two different drug injections that can be used to treat people who have been exposed to radioactive plutonium, americium or curium.

From BBC • May 16, 2023

Alternatively, Cotruvo suggests, captured americium and curium could be recycled back into nuclear fuel.

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

Monitors at the federal Hanford Nuclear site found plutonium and americium contamination up to 10 miles from a troubled demolition project that was suspended in December due to concerns about the spread of radioactive particles.

From Seattle Times • Jan. 25, 2018

One of the main concerns has been that the remaining plutonium was being allowed to degenerate into other radioactive components like americium, which emits gamma rays that travel farther and are hard to block.

From New York Times • Oct. 19, 2015