Element:	Magnesium
Symbol:	Mg
Atomic number:	12
Atomic weight:	24.3050(6)
Electron configuration:	[Ne] 3s2
Ground level:	1S0
Ionization potential:	7.6462 ev
Physical form:	Silvery-white metal
Melting point:	650°C
Boiling point:	1090°C
Critical temperature:
Density:	1.74 g/cm3
Specific heat:	1.023 J/g•K
Valence	2

Origin of name: Magnesia, district in Thessaly

Compounds of magnesium have long been known. Black recognized magnesium as an element in 1755. It was isolated by Davy in 1808, and prepared in coherent form by Bussy in 1831.

Magnesium is the eighth 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. The metal is now principally obtained in the U.S. by electrolysis of fused magnesium chloride derived from brines, wells, and sea water.

Magnesium 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. It is used in flashlight photography, flares, and pyrotechnics, including incendiary bombs. It is one third lighter than aluminum, 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. Calcined magnesia is also used for water treatment and in the manufacture of rubber, paper, etc. Organic magnesium compounds (Grignard’s reagents) are important.

Magnesium is an important element in both plant and animal life. Chlorophylls are magnesium-centered porphyrins. The adult daily requirement of magnesium is about 300 mg/day, but this is affected by various factors.

Great care should be taken in handling magnesium metal, especially in the finely divided state, as serious fires can occur. Water should not be used on burning magnesium or on magnesium fires.

Natural magnesium contains three isotopes. Twelve other isotopes are recognized.

Magnesium metal costs about $100/kg (99.8%).