Name Magnesium
Symbol Mg
Atomic Number 12
Atomic Mass 24.305 atomic mass units
Number of Protons 12
Number of Neutrons 12
Number of Electrons 12
Melting Point 650.0 C
Boiling Point 1107.0 C
Density 2.62 grams per cubic centimeter
Normal Phase Solid
Family Alkaline Earth Metals
Period 3
Cost $3.70 for 100 grams



Origin of Name From the Greek word Magnesia, a district of Thessaly
Date of Discovery 1808 in England
Discovered by Sir Humphry Davy
Common Compounds
Interesting facts
  • It is the eighth most common element in the earth's crust, but is the most commercially used element.
  • It is obtained from seawater.
  • It is a very flammable metal.
  • The center of chlorophyll contains magnesium.
  • Pouring water on burning magnesium will increase the fire and can cause explosions.
  • Magnesium oxide is the byproduct of burning magnesium and can cause respiratory problems like asthma or emphysema.
Common Uses
  • Photography flash products
  • Bombs
  • Signal flares
  • Medicines
  • Insulation
  • Paper
  • Fabrics
  • Cements
  • Ceramics
  • Cosmetics


Photo Courtesy of
Chemical Elements
General Chemistry Online

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