Encyclopedia of Metalloproteins

2013 Edition
| Editors: Robert H. Kretsinger, Vladimir N. Uversky, Eugene A. Permyakov

Calcium, Physical and Chemical Properties

Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-1533-6_414

Calcium is the fifth most abundant element in the earth’s crust. Some important, naturally occurring compounds are the carbonate (limestone), the sulfate, and complex silicates. It is a typical metal: it has the tendency to lose its outermost electrons and in doing so it achieves the inert gas electronic structure. Also its two outermost electrons are lost in one step. It is a ductile metal and can be formed by casting, extrusion, rolling, etc. The metal is used as a reducing agent, while CaO produced from limestone by calcination is used as a flux in iron and steel production, in gas desulfurization processes, and other metallurgical operations. Calcium hydroxide, obtained by dissolving CaO in water, is used as a pH control reagent in hydrometallurgy.

Both, gypsum, CaSO4·2H2O, and anhydrite, CaSO4, are widely distributed in the earth’s crust and are used as materials of construction.

Physical Properties

Atomic number


Atomic weight


Relative abundance, %


Density at 20°C


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  1. Hluchan S et al (1997) Calcium. In: Habashi F (ed) Handbook of extractive metallurgy. Wiley-VCH, Weinheim, pp 2250–2341Google Scholar

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  1. 1.Department of Mining, Metallurgical, and Materials EngineeringLaval UniversityQuebec CityCanada