beryllium

American  

[buh-ril-ee-uhm] / bəˈrɪl i əm /

noun

Chemistry.

1. a steel-gray, bivalent, hard, light, metallic element, the salts of which are sweet: used chiefly in copper alloys for better fatigue endurance, in springs, and in electrical contacts. Be; 9.0122; 4; 1.8 at 20° C.

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beryllium British  

/ bɛˈrɪlɪəm /

noun

1. Former names: glucinum.   glucinium.  a corrosion-resistant toxic silvery-white metallic element that occurs chiefly in beryl and is used mainly in X-ray windows and in the manufacture of alloys. Symbol: Be; atomic no: 4; atomic wt: 9.012; valency: 2; relative density: 1.848; melting pt: 1289°C; boiling pt: 2472°C

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beryllium Scientific  

/ bə-rĭl′ē-əm /

1. A hard, lightweight, steel-gray metallic element of the alkaline-earth group, found in various minerals, especially beryl. It has a high melting point and is corrosion-resistant. Beryllium is used to make sturdy, lightweight alloys and aerospace structural materials. It is also used as a neutron moderator in nuclear reactors. Atomic number 4; atomic weight 9.0122; melting point 1,278°C; boiling point 2,970°C; specific gravity 1.848; valence 2.

2. See Periodic Table

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Etymology

Origin of beryllium

1860–65; < Latin bēryll ( us ) beryl + -ium

Example Sentences

Concentrations of beryllium, copper, chromium, nickel and lead in particular were significantly above established safety thresholds for marine life, prompting fears for the long-term health of fish, marine mammals and the marine food chain.

From Los Angeles Times • Mar. 20, 2026

To generate the required beam, scientists accelerated Mo-92 ions and fired them at a beryllium target, producing fast moving Mo-86 nuclei.

From Science Daily • Mar. 8, 2026

Other elements found in Ukraine include beryllium and uranium, which are both crucial for nuclear weapons and reactors.

From BBC • Apr. 30, 2025

Loeb says traces of three rare elements — beryllium, lanthanum and uranium — suggest the spheres come from outside of our solar system.

From Salon • Sep. 1, 2023

For light elements like lithium and beryllium, the high yield was not particularly surprising, but the same thing happened with heavier atoms like gold and platinum.

From "Big Science" by Michael Hiltzik