magnesíum

Magnesíum, or magnesium, is the chemical element with symbol Mg and atomic number 12. It is a light, silvery-white alkaline earth metal that forms a thin oxide layer in air and burns with a bright white flame when finely divided.

It is abundant in the Earth's crust and in seawater, occurring in minerals such as magnesite and dolomite and as dissolved Mg2+ ions. Magnesium metal is lightweight, with a melting point of 650 °C and a boiling point of 1090 °C.

Industrial production relies mainly on electrolysis of magnesium chloride derived from brine or dolomite, while the Pidgeon process reduces magnesium oxide with silicon. Modern methods emphasize energy efficiency and environmental controls.

Magnesium is used as a primary alloying element in aluminum-magnesium alloys for automotive and aerospace parts, in die casting, and for structural components. Magnesium oxide and hydroxide are used as refractories, desiccants, and antacids.

In biology, magnesium is an essential mineral involved in more than 300 enzymatic reactions, energy production, and stabilizing nucleic acids and ribosomes. Dietary sources include leafy greens, nuts, seeds, whole grains, and dairy. Adequate intake is important for bone and muscle function.

Excess magnesium from supplements or kidney impairment can cause adverse effects; magnesium salts are used medically as laxatives and antacids under supervision.

Historically, magnesium was isolated by Humphry Davy in 1808 and named after Magnesia, a region in Greece. It has three stable isotopes: Mg-24, Mg-25, and Mg-26.