WHAT KIND OF METAL IS CALCIUM?

Calcium is one of a group of metals called the alkaline-earth metals. They form alkaline solutions with water and are found in many natural substances. Calcium is an important constituent of bones, making them hard and stable. Magnesium is found in chlorophyll, the green part of plants that can make energy from sunlight by photosynthesis. Alkaline-earth metals form the second group of the periodic table.

The chemical element Calcium (Ca), atomic number 20, is the fifth element and the third most abundant metal in the earth’s crust. The metal is trimorphic, harder than sodium, but softer than aluminium. A well as beryllium and aluminium, and unlike the alkaline metals, it doesn’t cause skin-burns. It is less chemically reactive than alkaline metals and then the other alkaline-earth metals.

Calcium ions solved in water form deposits in pipes and boilers and when the water is hard, that is, when it contains too much calcium or magnesium. This can be avoided with the water softeners. In the industry, metallic calcium is separated from the melted calcium chloride by electrolysis. This is obtained by treatment of carbonated minerals with chlorhydric acid, or like a sub product of the carbonates Solvay process.

In contact with air, calcium develops an oxide and nitride coating, which protects it from further corrosion. It burns in the air at a high temperature to produce nitride. The commercially produced metal reacts easily with water and acids and it produces hydrogen which contains remarkable amounts of ammonia and hydrocarbides as impurities.

The metal is used in aluminium alloys for bearings, as a helper in the bismuth removal form lead, as well as in controlling graphitic carbon in melted iron. It is also used as a deoxidizer in the manufacture of many steels; as a reducing agent in the preparation of metals as chromium, thorium, zirconium and uranium, and as separating material for gaseous mixtures of nitrogen and argon. Calcium is an alloying used in the production of aluminium, beryllium, copper, lead and magnesium alloys. It is also used in making cements and mortar that are used in buildings.

The calcium oxide, CaO, is produced by thermal decomposition of carbonated minerals in furnaces, applying a continuous bed process. The oxide is used in high intensity light arcs (lime light) for its unusual spectral characteristics and as dehydrating industrial agent. The metallurgic industry extensively uses the oxide during the reduction of ferrous alloys.

The pure calcium carbonate occurs in two crystalline forms: calcite, hexagonal shaped, which possesses birrefringent properties, and aragonite, rhombohedric. The natural carbonates are the most abundant calcium minerals. The Iceland spar and the calcite are essentially pure carbonate forms, whilst the marble is impure and much more compact, reason why it can be polished. It’s very demanded as construction material. Although the calcium carbonate is very little soluble in water, it is quite soluble if the water contains dissolved carbon dioxide, for in these solutions it forms bicarbonate when dissolving. This fact explains the cave formation, where the lime stone deposits have been in contact with acid waters.

Calcium is the fifth element and the third most abundant metal in the earth’s crust. The calcium compounds account for 3.64% of the earth’s crust. The distribution of calcium is very wide; it is found in almost every terrestrial area in the world. This element is essential for the life of plants and an animal, for it is present in the animal’s skeleton, in tooth, in the egg’s shell, in the coral and in many soils. Seawater contains 0.15% of calcium chloride. Calcium cannot be found alone in nature. Calcium is found mostly as limestone, gypsum and fluorite. Stalagmites and stalactites contain calcium carbonate.

Calcium is always present in every plant, as it is essential for its growth. It is contained in the soft tissue, in fluids within the tissue and in the structure of every animal’s skeleton. The vertebrate’s bones contain calcium in the form of calcium fluoride, calcium carbonate and calcium phosphate.

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