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Atomic Number: | 12 | Atomic Symbol: | Mg | Atomic Weight: | 24.305 | Electron Configuration: | 2-8-2 | Shells: | 2,8,2 | Filling Orbital: | 3s2 | Melting Point: | 638.8oC | Boiling Point: | 1090oC | Uses: | Racing bikes, in alloys to make airplanes, missiles |
History(Magnesia, district in Thessaly) Compounds of magnesium have
long been known. Black recognized magnesium as an element in 1755. Davy isolated
it in 1808 and Bussy prepared it in coherent form in 1831. Magnesium is the
eigth most abundant element in the earth's crust. It does not occur uncombined,
but is found in large deposits in the form of magnesite, dolomite, and other
minerals.
SourcesThe metal is now principally obtained in the U.S. by
electrolysis of fused magnesium chloride derived from brines, wells, and sea
water.
PropertiesMagnesium is a light, silvery-white, and fairly tough metal.
It tarnishes slightly in air, and finely divided magnesium readily ignites upon
heating in air and burns with a dazzling white flame.
UsesUses include flashlight photography, flares, and pyrotechnics,
including incendiary bombs. It is one third lighter than aluminium, and in
alloys is essential for airplane and missile construction. The metal improves
the mechanical, fabrication, and welding characteristics of aluminum when used
as an alloying agent. Magnesium is used in producing nodular graphite in cast
iron, and is used as an additive to conventional propellants.
It is also used as a reducing agent in the production of pure uranium and
other metals from their salts. The hydroxide (milk of magnesia), chloride,
sulfate (Epsom salts), and citrate are used in medicine. Dead-burned magnesite
is employed for refractory purposes such as brick and liners in furnaces and
converters.
CompoundsOrganic magnesium is important in both plant and animal life.
Chlorophylls are magnesium-centered perphyrins.
The adult daily nutritional requirement, which is affected by various factors
include weight and size, is about 300 mg/day.
HandlingBecause serious fires can occur, great care should be taken in
handling magnesium metal, especially in the finely divided state. Water should
not be used on burning magnesium or on magnesium fires.
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