Author of the description: 
Gruiz Katalin

Atomic number


Atomic mass

24.305 g.mol -1




1.74 -3 at 20 °C

Melting point

650 °C

Boiling point

1107 °C

Vanderwaals radius

0.16 nm

Ionic radius

0.065 nm



Electronic shell

[Ne] 3s2

Energy of first ionisation

737.5 kJ.mol -1

Energy of second ionisation

1450 kJ.mol -1

Standard potential

- 2.34 V

Discovered by

Sir Humphrey Davy in 1808


Chemical element, metallic, symbol Mg, situated in group IIa in the periodic table, atomic number: 12, atomic weight: 24,312. Magnesium is silvery white and very light. Its relative density is 1,74 and it’s density 1740 kg/m3 (0.063 lb/in3 or 108.6 lb/ft3). Magnesium is known for a long time as the lighter structural metal in the industry, due to it’s low weight and to it’s capability of forming mechanically resistant alloys.

Magnesium is very chemically active, it takes the place of hydrogen in boiling water and a great number of metals can be produced by thermic reduction of its salts and oxidized forms with magnesium. It joins together with most non-metals and almost every acid. Magnesium reacts only slightly or not at all with most of the alkalis and many organic substances, like hydrocarbons, aldehides, alcohols, phenols, amines, esters and most of the oils. Used as a catalyst, magnesium promotes organic reactions of condensation, reduction, addition and dehalogenization. It was used for a long time for synthesizing special and complex organic components by the well-known Grignard reaction. The main ingredients of the alloys are: aluminum, manganese, zircon, zinc, rare-earth metals and thorium.


Magnesium compounds are used as refractory material in furnace linings for producing metals (iron and steel, nonferrous metals), glass, and cement.
With a density of only two thirds of the aluminum’s, it has countless applications in cases where weight reducing is important, i.e. in aeroplane and missile construction. It also has many useful chemical and metallurgic properties, which make it appropriate for many other non-structural applications.
Magnesium components are widely used in industry and agriculture.
Other uses include: removal of sulphur form iron and steel, photoengraved plates in the printing industry; reducing agent for the production of pure uranium and other metals from their salts; flashlight photography, flares, and pyrotechnics.