Magnesium

Magnesium (Mg)

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.
Atomic Number12
Atomic Weight24.305
Mass Number24
Group2
Period3
Blocks
Protons12 p+
Neutrons12 n0
Electrons12 e-
Magnesium crystals.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
150 pm
Atomic Volume
Covalent Radius
139 pm
Metallic Radius
136 pm
Ionic Radius
57 pm
Crystal Radius
71 pm
Van der Waals radius
173 pm
Density
1.74 g/cm³
Boiling Point
1,363 K
Melting Point
922 K
Electrons per shell2, 8, 2
Electronegativity
1.31
Electrophilicity
Proton Affinity
819.6 kJ/mol
Electron Affinity
Ionization Potential
7.646235 eV/particle
Heat of Vaporization
131.8 kJ/mol
Heat of Fusion
9.2 kJ/mol
Heat of Formation
147.1 kJ/mol
Molar Heat Capacity
24.869 J/(mol K)
Specific Heat Capacity
1.023 J/(g⋅K)
Thermal Conductivity
Gas Basicity
797.3 kJ/mol
Dipole Polarizability
71.2 a₀
C6 Dispersion Coefficient
626 a₀
Oxidation States1, 2
Color
Silver
Crystal StructureSimple Hexagonal (HEX)
Lattice Constant
3.21 Å
Bulk Modulus
Electrical Resistivity
Electron Configuration[Ne] 3s2
Magnetic Ordering
Magnetic Susceptibility
PhaseSolid
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryAlkaline earth metals, Alkaline earth metals
CAS GroupIIA
IUPAC GroupIIA
Glawe Number73
Mendeleev Number76
Pettifor Number73
Geochemical Classmajor
Goldschmidt Classlitophile
Radioactivity
RadioactiveNo
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
23,300 mg/kg
Abundance in Oceans
1,290 mg/L
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universe0.06%

Isotopes of Magnesium

Stable Isotopes
24Mg 25Mg 26Mg
Unstable Isotopes
19Mg 20Mg 21Mg 22Mg 23Mg 27Mg 28Mg 29Mg 30Mg 31Mg 32Mg 33Mg 34Mg 35Mg 36Mg 37Mg 38Mg 39Mg 40Mg

History

Scottish chemist Joseph Black recognized magnesium as an element in 1755. Magnesium was first isolated by Sir Humphry Davy in 1808, in London. He used electrolysis on a mixture of magnesia and mercuric oxide. Antoine Bussy prepared it in coherent form in 1831. From Magnesia, district in Thessaly

DiscoverersSir Humphrey Davy
Discovery LocationEngland
Discovery Year1808
Name OriginFrom Magnesia ancient city in district of Thessaly, Greece.
Because serious fires can occur, great care should be taken in handling magnesium metal
When it burns in air, magnesium produces a brilliant white light

Uses

Magnesium is widely used in the manufacturing of mobile phones, laptop computers, cameras, and other electronic components. The brilliant light it produces when ignited is made use of in photography, flares, pyrotechnics and incendiary bombs. Magnesium compounds such as the hydroxide (milk of magnesia), sulfate (Epsom salts), chloride and citrate are used for medicinal purposes. Used in alloys to make airplanes, missiles and other uses for light metals. Has structural properties similar to aluminium. But since it is flammable at temperatures of burning gasoline, its uses are limited.

Sources

Usually obtained by electrolysis of melted magnesium chloride (MgCl2) found in sea water. Each cubic mile of seawater contains about 12 billion pounds of magnesium.