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

The macrophages then released calcium ions directly to the muscle fibers, accelerating early stages of healing.

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The findings were consistent with previous work on chromium, calcium, titanium, and zirconium isotopes: Earth and Moon show no measurable differences in these ratios.

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Some of these animals can photosynthesize like plants; some harvest algae and seawater to make calcium carbonate for their underwater castles; some produce their own light or glow in the dark.

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In 1964, we received great medical news—that the slower heartbeat, loss of calcium in bones, pooling of blood in the legs, and other effects of weightlessness seemed to be temporary.

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Strontium 90 is chemically similar to calcium, and so it is absorbed by the body and deposited in the bones.

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