calcium

American  

[kal-see-uhm] / ˈkæl si əm /

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 British  

/ 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 Scientific  

/ 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

---

Etymology

Origin of calcium

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

Example Sentences

Those nerve fibers release norepinephrine, a neurotransmitter that binds to the fibroblasts and causes a spike in calcium levels inside the cells.

From Science Daily

In particular, calcium ions can be difficult to move efficiently within a battery, and maintaining stable performance over repeated charge and discharge cycles has proven challenging.

From Science Daily

The researchers point out that much of the calcium carbonate produced by plankton does not sink all the way to the ocean floor.

From Science Daily

For ravens, the eggs provide a nutritious meal, packed with calcium and albumen.

From Los Angeles Times

This protein regulates the flow of calcium inside muscle cells, acting as a gate that opens only when muscles need to contract.

From Science Daily