calcium

[kal-see-uhm]

noun

Chemistry, Biology.

1. a silver-white divalent metal, occurring combined in limestone, chalk, gypsum, etc., occurring also in vertebrates and other animals, as a component of bone, skeletal mass, shell, etc., and as a necessary element in nerve conduction, heartbeat, muscle contraction, and many other physiological functions. Ca; 40.08; 20; 1.55 at 20°C.

calcium

/ ˈkælsɪəm /

noun

1. a malleable silvery-white metallic element of the alkaline earth group; the fifth most abundant element in the earth's crust (3.6 per cent), occurring esp as forms of calcium carbonate. It is an essential constituent of bones and teeth and is used as a deoxidizer in steel. Symbol: Ca; atomic no: 20; atomic wt: 40.078; valency: 2; relative density: 1.55; melting pt: 842±2°C; boiling pt: 1494°C

calcium

1. A silvery-white, moderately hard metallic element of the alkaline-earth group that occurs in limestone and gypsum. It is a basic component of leaves, bones, teeth, and shells, and is essential for the normal growth and development of most animals and plants. Calcium is used to make plaster, cement, and alloys. Atomic number 20; atomic weight 40.08; melting point 842 to 848°C; boiling point 1,487°C; specific gravity 1.55; valence 2.

2. See Periodic Table

Word History and Origins

Origin of calcium¹

First recorded in 1800–10; calc- + -ium

Word History and Origins

Origin of calcium¹

C19: from New Latin, from Latin calx lime

Example Sentences

Over decades, Los Angeles’ reliance on water from nearby creeks lowered the lake level and left exposed its craggy tufa towers, formations of calcium carbonate that grew underwater around springs.

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Over time, this scaffold continues to attract calcium and phosphate ions, leading to the growth of a protective enamel-like coating around the tooth, according to researchers.

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Garrett stops to describe how the towers of calcium carbonate grew underwater around freshwater springs over thousands of years, then were left exposed as the water dropped.

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Visitors who stroll beside the lapping water take photos of the craggy calcium carbonate formations as flocks of migratory birds soar overhead.

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Adults are less sensitive to lead, but under much higher concentrations — beyond 40 mcg/dL — the metal, which the body mistakes for calcium, can damage many organs.

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