Magnesium
Magnesium General
Name:Magnesium | Symbol:Mg |
Type:Alkali Earth Metal | Atomic weight:24.305 |
Density @ 293 K: 1.738 g/cm3 | Atomic volume:13.97 cm3/mol |
Discovered:
Scottish chemist Joseph Black recognized magnesium as an element in 1755. He showed by experiment that it differed from calcium, which it had previously been thought to be. Black wrote, "We have already shewn by experiment, that magnesia alba [magnesium carbonate] is a compound of a peculiar earth and fixed air." (1) By peculiar, Black meant a new earth metal. |
Magnesium States
State (s, l, g):solid | |
Melting point:923 K (650 °C) | Boiling point:1363 K (1090 °C) |
Magnesium Energies
Specific heat capacity:1.02 J g-1 K-1 | Heat of atomization: 146 kJ mol-1 |
Heat of fusion:8.48 kJ mol-1 | Heat of vaporization :127.4 kJ mol-1 |
1st ionization energy:737.7 kJ mol-1 | 2nd ionization energy:1450.6 kJ mol-1 |
3rd ionization energy:7732.6 kJ mol-1 | Electron affinity: 78 kJ mol-1 |
Magnesium Oxidation & Electrons
Shells:2,8,2 | Electron configuration:[Ne] 3s2 |
Minimum oxidation number: 0 | Maximum oxidation number:2 |
Min. common oxidation no.: 0 | Max. common oxidation no.:2 |
Electronegativity (Pauling Scale):1.31 | Polarizability volume:10.6 Å3 |
Magnesium Appearance & Characteristics
Structure:hcp: hexagonal close packed | Color:silvery-white |
Hardness:2.5 mohs | |
Harmful effects:
Magnesium powder is an explosive hazard. |
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Characteristics:
Magnesium is a silvery-white, low density, reasonably strong metal that tarnishes in air to form a thin oxide coating. Magnesium and its alloys have very good corrosion resistance and good high temperature mechanical properties. Uses: The brilliant light it produces when ignited is made use of in photography, flares, pyrotechnics and incendiary bombs. |
Magnesium Reactions
Reaction with air:vigorous, w/ht ⇒ MgO, Mg3N2 | Reaction with 6 M HCl:mild ⇒ H2, MgCl2 |
Reaction with 15 M HNO3:vigorous ⇒ NOx, Mg(NO3)2 | Reaction with 6 M NaOH: none |
Magnesium Compounds
Oxide(s):MgO | Chloride(s):MgCl2 |
Hydride(s):MgH2 |
Magnesium Radius
Atomic radius:150 pm | Ionic radius (1+ ion):pm |
Ionic radius (2+ ion):86 pm | Ionic radius (3+ ion):pm |
Ionic radius (2- ion):pm | Ionic radius (1- ion):pm |
Magnesium Conductivity
Thermal conductivity:156 W m3 K3 | Electrical conductivity:22.4 x 106 S cm3 |
Magnesium Abundance & Isotopes
Abundance earth's crust: 2.3 % by weight, 2.0 % by moles | |
Abundance solar system:700 parts per million by weight, 30 parts per million by moles | |
Cost, pure:$3.7 per 100g | |
Cost, bulk:$0.29 per 100g | |
Source:
Magnesium is the eighth most abundant element in the Earth's crust and the sixth most abundant metal. Magnesium is obtained commercially by the 'Pidgeon' process. This high temperature method uses silicon as a reducing agent to extract magnesium from minerals such as dolomite (MgCa(CO 3)2) or magnesite (MgCO 3) or saltwater. |
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Isotopes:
Magnesium has 15 isotopes whose half-lives are known with mass ranges from 20 to 34. Of these 3 are stable, 24Mg, 25Mg and 26Mg. Isotope 24Mg is the most abundant (79%). |
Magnesium Other
Other:
References |
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