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

/ kăl′sē-əm /

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

Then the six fibers, along with an extra fiber to boost the calcium signal's measurement, were incorporated into a 2.5-millimeter-thick catheter to create a cerebrospinal fluid sensing system.

From Science Daily

In their first experiments, they measured the activity of the cells as the bladder empties by measuring changes in levels of calcium.

From Science Daily

Heart cockles and many other marine animals use a special form of calcium carbonate called aragonite to make their shells.

From Science Daily

Many people assume both ice cream and gelato are good sources of calcium, presumably because they're made from dairy products.

From Salon

Without the constant pressure of gravity on the skeletal system, calcium from bones leaches into the body, which besides weakening the bones themselves can lead astronauts to be at higher risk of developing kidney stones.

From Salon