Elemental Calcium: Properties, History & Preparation

Calcium is a silver-gray metal that is widely distributed in nature with other elements, particularly oxygen, carbon, silicon, phosphorus and fluorine. It plays an essential role in plant and animal growth.

History

• In 1808, Sir Humphrey Davy isolated calcium in an impure state by electrolysis of moist lime with a mercury cathode. The pure metal was prepared by a French chemist, Henri Moissan, in 1898, by heating calcium iodide with metallic sodium.

Preparation

• On a small scale, calcium is prepared by reducing anhydrous calcium salt with metallic aluminum or sodium. In industry, the metal is produced by electrolysis of fused calcium chloride.

Physical Properties

• Calcium is generally a soft metallic element, but it is harder than lead. It is malleable and ductile, having a melting point of 1,542.2 degrees F and a boiling point of 2,703.2 degrees F. It is a good conductor of heat and electricity.

Chemical Properties

• Calcium is readily tarnished in moist air with the formation of a surface layer of oxide and nitrite. When heated in air or oxygen, it burns brilliantly.

Uses

• Calcium is used as a deoxidizer in metallurgy. It is a convenient reducing agent in the laboratory, and is used for removing nitrogen and hydrogen from gas streams.