The element name "calcium" comes from the Latin word "calcis" or "calx" meaning "lime". In addition to occurrence in lime (calcium carbonate), calcium is found in the minerals gypsum (calcium sulfate) and fluorite (calcium fluoride).Touching calcium metal can cause irritation or even chemical burns. Pure calcium metal reacts vigorously and sometimes violently with water and acids. The reaction is exothermic.The calcium oxide was mixed with water to make cement, which was mixed with stones to build aqueducts, amphitheaters, and other structures that survive to the present day. Calcium is used for making cement, making cheese, removing nonmetallic impurities from alloys, and as a reduction agent in the preparation of other metals. The Romans used to heat limestone, which is calcium carbonate, to make calcium oxide.Excessive consumption would be on the order of 10 g calcium carbonate/day, though symptoms have been reported upon ingesting as little as 2.5 g calcium carbonate daily. Excessive calcium consumption has been linked to kidney stone formation and artery calcification. While calcium and its compounds are not considered to be toxic, ingesting too many calcium carbonate dietary supplements or antacids can cause milk-alkali syndrome, which is associated with hypercalcemia sometimes leading to fatal renal failure. Calcium supplementation is controversial.Vitamin D is converted to a hormone which causes intestinal proteins responsible for calcium absorption to be produced. Vitamin D is essential for calcium absorption by the human body.Other sources of calcium include protein-rich foods, vegetables, and fruits. Dairy products and grains are the primary sources of dietary calcium, accounting or about three-quarters of dietary intake.
If you could extract all of the calcium from the average adult person, you'd have about 2 pounds (1 kilogram) of the metal. Calcium in the form of calcium carbonate is used by snails and shellfish to construct shells. Calcium participates in many biochemical reactions, including building skeletal systems, cell signaling, and moderating muscle action. It is the most abundant metal in the human body, found mainly in bones and teeth. The element is essential for animal and plant nutrition.It is present at about 70 parts per million by weight in the solar system. Natural calcium is a mixture of six isotopes, with the most abundant (97 percent) being calcium-40.
The only metals more abundant in the crust are iron and aluminum.
#Ca element chemistry free#
Calcium isn't found free in nature, but it can be purified into a soft silvery-white alkaline earth metal. It has the periodic table symbol Ca and an atomic weight of 40.078. Calcium is element atomic number 20 on the periodic table, which means each atom of calcium has 20 protons.
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