gallium

American  

[gal-ee-uhm] / ˈgæl i əm /

noun

Chemistry.

1. a rare, steel-gray, trivalent metallic element used in high-temperature thermometers because of its high boiling point (1983°C) and low melting point (30°C). Ga; 69.72; 31; 5.91 at 20°C.

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gallium British  

/ ˈɡælɪəm /

noun

1. a silvery metallic element that is liquid for a wide temperature range. It occurs in trace amounts in some ores and is used in high-temperature thermometers and low-melting alloys. Gallium arsenide is a semiconductor. Symbol: Ga; atomic no: 31; atomic wt: 69.723; valency: 2 or 3; relative density: 5.904; melting pt: 29.77°C; boiling pt: 2205°C

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gallium Scientific  

/ găl′ē-əm /

1. A rare, silvery metallic element that is found as a trace element in coal, in bauxite, and in several minerals. It is liquid near room temperature and expands when it solidifies. It is used in thermometers and semiconductors. Atomic number 31; atomic weight 69.72; melting point 29.78°C; boiling point 2,403°C; specific gravity 5.907; valence 2, 3.

2. See Periodic Table

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Etymology

Origin of gallium

1870–75; < New Latin, equivalent to Latin gall ( us ) cock (translation of French coq, from Lecoq de Boisbaudran, 19th-century French chemist) + New Latin -ium -ium

Example Sentences

It’s harder than ever to buy the rare metal gallium from China for your high-tech military radar system—but it’s easier than ever to buy Chinese soft-serve ice cream in the U.S.

From Barron's • Jun. 1, 2026

Earlier versions of such gratings, made from materials like silicon or gallium compounds, required thicknesses of several hundred nanometers to function effectively.

From Science Daily • Apr. 5, 2026

"There is a dramatic change in the lattice when you shine light on it, a unique phenomenon that you don't see with silicon or gallium arsenide," Leite said.

From Science Daily • Mar. 31, 2026

Small market minerals like gallium are good targets for government stockpiling because they are especially vulnerable to supply disruption.

From Barron's • Mar. 9, 2026

Other elements predicted and characterized by Mendel�eff which have been since realized are gallium, discovered in 1875, and germanium, discovered in 1885 by Clemens Winkler.

From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 1 "Châtelet" to "Chicago" by Various