(Chemical symbol: Mg). A light, white and fairly tough metal. It tarnishes slightly in air, and when fabricated into ribbon, wire or powder, ignites on heating and bums with a dazzling white flame. Magnesium is one of the most abundant elements; it is eighth in estimated amount in the earth’s crust. It is removed commercially from sea water in the form of magnesium chloride (a mineral similar to table salt). Pure magnesium is obtained from molten magnesium chloride by the electrolysis process; the magnesium collects on the cathode. Atomic weight 24.32; atomic number, 12; melting point 651°C (1204°F); boiling point 1110°C (2030°F).

In the pure state, magnesium does not have sufficient strength or other properties to make it suitable for structural purposes. However, it alloys readily with aluminum, zinc, silicon, manganese and tin, to form a variety of structural alloys. The strength of these alloys is comparable to aluminum alloys but they weigh only 65% as much as aluminum. See MAGNESIUM ALLOYS.

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