cal·ci·um   (kāl'sē-əm)    n.   Symbol Ca A silvery, moderately hard metallic element that constitutes approximately 3 percent of the earth's crust and is a basic component of most animals and plants. It occurs naturally in limestone, gypsum, and fluorite, and its compounds are used to make plaster, quicklime, Portland cement, and metallurgic and electronic materials. Atomic number 20; atomic weight 40.08; melting point 842 to 848°C; boiling point 1,487°C; specific gravity 1.55; valence 2. See Table at element. [Latin calx, calc-, lime; see calx + -ium.]

Calcium

Cal"ci*um\ (k[a^]l"s[i^]*[u^]m), n. [NL., from L. calx, calcis, lime; cf F. calcium. See Calx.] (Chem.) An elementary substance; a metal which combined with oxygen forms lime. It is of a pale yellow color, tenacious, and malleable. It is a member of the alkaline earth group of elements. Atomic weight 40. Symbol Ca.

Note: Calcium is widely and abundantly disseminated, as in its compounds calcium carbonate or limestone, calcium sulphate or gypsum, calcium fluoride or fluor spar, calcium phosphate or apatite.

Calcium light, an intense light produced by the incandescence of a stick or ball of lime in the flame of a combination of oxygen and hydrogen gases, or of oxygen and coal gas; -- called also Drummond light.

calcium 

Main Entry: cal·ci·um
Pronunciation: 'kal-sE-&m
Function: noun
often attributive : a silver-white bivalent metallic element that isan alkaline earth metal, occurs only in combination, and is an essential constituent of most plants and animals —symbol Ca; —see ELEMENT table

calcium cal·ci·um (kāl'sē-əm)
n.
Symbol Ca
A soft metallic element that is a basic component of animals and plants and constitutes [approx] 3 percent of Earth's crust. It occurs naturally in limestone, gypsum, and fluorite. Atomic number 20; atomic weight 40.08; melting point 842°C; boiling point 1,484°C; specific gravity 1.55; valence 2.

calcium   (kāl'sē-əm)  Pronunciation Key  Symbol Ca 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. See Periodic Table.