strontium

American  

[stron-shee-uhm, -shuhm, -tee-uhm] / ˈstrɒn ʃi əm, -ʃəm, -ti əm /

noun

Chemistry.

1. a bivalent, metallic element whose compounds resemble those of calcium, found in nature only in the combined state, as in strontianite: used in fireworks, flares, and tracer bullets. Sr; 87.62; 38; 2.6.

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strontium British  

/ ˈstrɒntɪəm /

noun

1. a soft silvery-white element of the alkaline earth group of metals, occurring chiefly in celestite and strontianite. Its compounds burn with a crimson flame and are used in fireworks. The radioisotope strontium-90, with a half-life of 28.1 years, is used in nuclear power sources and is a hazardous nuclear fall-out product. Symbol: Sr; atomic no: 38; atomic wt: 87.62; valency: 2; relative density: 2.54; melting pt: 769°C; boiling pt: 1384°C

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strontium Scientific  

/ strŏn′chē-əm,-tē-əm /

1. A soft, silvery metallic element of the alkaline-earth group that occurs naturally only as a sulfate or carbonate. One of its isotopes is used in the radiometric dating of rocks. Because strontium salts burn with a red flame, they are used to make fireworks and signal flares. Atomic number 38; atomic weight 87.62; melting point 777°C; boiling point 1,382°C; specific gravity 2.54; valence 2.

2. See Periodic Table

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Other Word Forms

• strontic adjective

Etymology

Origin of strontium

First recorded in 1800–10; stront(ia) + -ium

Example Sentences

Minerals in the powder, including strontium, calcium, and barium, formed deposits on the tooth surface, rebuilding key structures.

From Science Daily • Mar. 23, 2026

Carbon and nitrogen isotopes reveal long-term diet, while strontium isotopes indicate where a person lived and whether they moved during their lifetime.

From Science Daily • Mar. 21, 2026

The researchers were able to measure carbon, oxygen, strontium and lead isotopes from the tooth which revealed changes to the animal's diet with the seasons and showed seasonal food sources came from different geological areas.

From BBC • Aug. 22, 2025

Whether its lead from old buildings, arsenic from contaminated food or strontium fallout from a nuclear explosion, heavy metals that enter the body pose a serious health threat.

From Los Angeles Times • Oct. 31, 2024

Of course, the radioactive strontium they ate was concentrated in their bones, and the radioactive iodine was concentrated in their thyroids.

From "Cosmos" by Carl Sagan