Calcium: Difference between revisions
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imported>Milton Beychok m (Copy edits of infobox data) |
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|no4= | |no4= | ||
|properties=Silvery-white, hard metal. | |properties=Silvery-white, hard metal. | ||
|compounds=oxide | |compounds=oxide, carbonate, nitrate, sulfide, chloride, and others | ||
|uses= | |uses= | ||
|hazard= | |hazard=Reacts violently with water and acids to release explosive hydrogen, | ||
}} | }} | ||
'''Calcium''' is | |||
'''Calcium''' is a [[Chemical elements|chemical element]], having the [[chemical symbol]] Ca. Its [[atomic number]] (the number of [[proton]]s) is 20. It has a [[Atomic mass#Standard atomic weights of the elements|standard atomic weight]] of 40.078 g•mol<sup> −1</sup>, and is a [[solid]] in its elemental form. | |||
Calcium is considered to be a member of the "alkaline earth metal" class of element. At a [[pressure]] of 101.325 k[[Pascal (unit)|Pa]], it has a [[boiling point]] of 1,484 °[[Celsius (unit)|C]], and a [[melting point]] of 842 °C. | |||
Calcium is essential for [[life]], particularly in [[cell]] [[physiology]], where movement of the calcium ion Ca<sup>2+</sup> into and out of the cytoplasm functions as a signal for many cellular processes, including neuromuscular contractions. It is also a major material used in mineralization of bones, teeth and shells. | Calcium is essential for [[life]], particularly in [[cell]] [[physiology]], where movement of the calcium ion Ca<sup>2+</sup> into and out of the cytoplasm functions as a signal for many cellular processes, including neuromuscular contractions. It is also a major material used in mineralization of bones, teeth and shells. | ||
Revision as of 00:53, 19 April 2011
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Calcium is a chemical element, having the chemical symbol Ca. Its atomic number (the number of protons) is 20. It has a standard atomic weight of 40.078 g•mol −1, and is a solid in its elemental form.
Calcium is considered to be a member of the "alkaline earth metal" class of element. At a pressure of 101.325 kPa, it has a boiling point of 1,484 °C, and a melting point of 842 °C.
Calcium is essential for life, particularly in cell physiology, where movement of the calcium ion Ca2+ into and out of the cytoplasm functions as a signal for many cellular processes, including neuromuscular contractions. It is also a major material used in mineralization of bones, teeth and shells.