'Magnesium' definitions:

Definition of 'magnesium'

From: WordNet
noun
A light silver-white ductile bivalent metallic element; in pure form it burns with brilliant white flame; occurs naturally only in combination (as in magnesite and dolomite and carnallite and spinel and olivine) [syn: magnesium, Mg, atomic number 12]

Definition of 'Magnesium'

From: GCIDE
  • Magnesium \Mag*ne"si*um\, n. [NL. & F. See Magnesia.] (Chem.) A light silver-white metallic element of atomic number 12, malleable and ductile, quite permanent in dry air but tarnishing in moist air. It burns, forming (the oxide) magnesia, with the production of a blinding light (the so-called magnesium light) which is used in signaling, in pyrotechny, or in photography where a strong actinic illuminant is required. Its compounds occur abundantly, as in dolomite, talc, meerschaum, etc. Symbol Mg. Atomic weight, 24.305. Specific gravity, 1.75. [1913 Webster]
  • Magnesium sulphate. (Chem.) Same as Epsom salts. [1913 Webster]

Definition of 'Magnesium'

From: Elements
  • Symbol: Mg
  • Atomic number: 12
  • Atomic weight: 24.312
  • Silvery metallic element belonging to group 2 of the periodic table (alkaline-earth metals). It is essential for living organisms, and is used in a number of light alloys. Chemically very reactive, it forms a protective oxide coating when exposed to air and burns with an intense white flame. It also reacts with sulphur, nitrogen and the halogens. First isolated by Bussy in 1828.