magnésíum

Magnésíum is a chemical element with the symbol Mg and atomic number 12. It is a light, silvery-white alkaline earth metal in group 2 of the periodic table. It is the eighth most abundant element in the Earth's crust and is prevalent in seawater as Mg2+ ions. Common minerals include magnesite (MgCO3) and dolomite (CaMg(CO3)2).

Magnesíum is highly reactive, forming a protective oxide layer in air. It burns with a bright white flame when ignited. The element typically exhibits a +2 oxidation state.

Industrial production relies on separating magnesium from its compounds. Major sources are magnesite and dolomite, from which MgO is produced and reduced to metal or converted to MgCl2 for electrolytic reduction. Modern processes use electrolysis of molten MgCl2 derived from brines and rock salt.

Uses include aerospace and automotive alloys with aluminum for lightweight structures; production of refractory materials, cement, and chemical syntheses. Magnesium compounds such as magnesium oxide (MgO) and magnesium sulfate (MgSO4) have wide uses as refractory materials, laxatives, and anticaking agents. In pyrotechnics, magnesium provides a bright white flame.

Biologically, magnésíum is an essential nutrient for plants, animals, and humans. It acts as a cofactor for many enzymes and is central to energy production, DNA and RNA synthesis, and nerve and muscle function. Dietary deficiency can cause cramps, weakness, and heart rhythm disturbances; excessive magnesium mainly threatens people with kidney impairment or when taken in large laxative doses.

Historically, magnésíum was isolated in 1808 by Sir Humphry Davy through electrolysis of magnesia and named after Magnesia, a region in Greece.