(From magnesia) A lightweight, silver-white, malleable and ductile, metallic chemical element, one of the alkaline-earth metals, used in making several alloys and, because it burns with a hot, white light, in photographic flashbulbs, incendiary bombs, etc.

Symbol: Mg
Atomic number: 12
Atomic weight: 24.3050
Density (at room temperature and pressure): 1.738 g/cc
Melting point: 650°C
Boiling point: 1,090°C
Main valence: +2
Ground state electron configuration: [Ne]3s2