barium

American  

[bair-ee-uhm, bar-] / ˈbɛər i əm, ˈbær- /

noun

Chemistry.

1. a whitish, malleable, active, divalent, metallic element, occurring in combination chiefly as barite or as witherite. Ba; 137.34; 56; 3.5 at 20°C.

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barium British  

/ ˈbɛərɪəm /

noun

1. a soft silvery-white metallic element of the alkaline earth group. It is used in bearing alloys and compounds are used as pigments. Symbol: Ba; atomic no: 56; atomic wt: 137.327; valency: 2; relative density: 3.5; melting pt: 729°C; boiling pt: 1805°C

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barium Scientific  

/ bâr′ē-əm /

1. A soft, silvery-white metallic element of the alkaline-earth group. It occurs only in combination with other elements, especially in barite. Barium compounds are used in x-raying the digestive system and in making fireworks and white pigments. Atomic number 56; atomic weight 137.33; melting point 725°C; boiling point 1,140°C; specific gravity 3.50; valence 2.

2. See Periodic Table

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Etymology

Origin of barium

First recorded in 1800–10; bar(ytes) + -ium

Example Sentences

See Examples For:

barium

With the proposed StormWall, six satellites in geosynchronous orbit would release hundreds of thousands of pounds of material, such as barium, lithium or sodium.

From The Wall Street Journal ● Jul. 10, 2026

A significant expense would be the launch itself: The system would require 838,000 pounds of ionizable material—lithium, barium or sodium—to be lofted to an altitude of 22,000 miles above Earth’s surface.

From The Wall Street Journal ● Jul. 10, 2026

The Environmental Protection Agency does not consider it a carcinogen; however, exposure to barium can cause gastrointestinal irritation, cardiovascular effects, kidney damage and respiratory problems.

From Los Angeles Times ● May 4, 2025

They found increased salinity and high concentrations of heavy metals in water nearer oil wells, as well as high concentrations of lead and barium in human hair samples.

From BBC ● Nov. 10, 2024

A poor pharmacist with little in the way of advanced apparatus, he discovered eight elements–chlorine, fluorine, manganese, barium, molybdenum, tungsten, nitrogen, and oxygen–and got credit for none of them.

From "A Short History of Nearly Everything" by Bill Bryson