General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles


Name Magnesium Symbol Mg
atomic number 12 Atomic weight 24.305
Density @ 293 K 1.738 g/cm3 Atomic volume 13.97 cm3/mol
Group Alkali Earth discovered 1808


state (s, l, g) s
melting point 922 K boiling point 1378 K
Heat of fusion 8.954 kJ/mol Heat of vaporization 127.40 kJ/mol
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1st ionization energy 737.7 kJ/mole electronegativity 1.31
2nd ionization energy 1450.6 kJ/mole electron affinity kJ/mole
3rd ionization energy 7732.6 kJ/mole Specific heat 1.02 J/gK
heat atomization 148 kJ/mole atoms

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
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Appearance & Characteristics

structure hcp: hexagonal close pkd color silvery
uses alloys, flash bulbs toxicity
hardness 2 mohs characteristics burns brightly


reaction with air vigorous,w/ht = MgO,Mg3N2 reaction with 6M HCl mild, = H2, MgCl2
reaction with 6M HCl mild, = H2, MgCl2 reaction with 15M HNO3 vigorous, = NOx, Mg(NO3)2
reaction with 6M NaOH none
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Other Forms

number of isotopes 3 hydride(s) MgH2
oxide(s) MgO chloride(s) MgCl2


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 160 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) 86 pm ionic radius (3+ ion) pm
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thermal conductivity 156 J/m-sec-deg electrical conductivity 224.719 1/mohm-cm
polarizability 10.6 A^3


source Seawater, magnesite rel. abund. solar system 6.031 log
abundance earth's crust 4.4 log cost, pure 3.7 $/100g
cost, bulk 0.32 $/100g
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World Wide Web presentation of Chemicool Periodic Table is © Copyright 1996-99 by David D. Hsu. Some data were provided by and used with the permission of JCE Software and is owned and copyright by the Division of Chemical Education, Inc. Additional data were provided by Perkin-Elmer through Peter Lykos of IIT. The information may not be redistributed without the permission of David Hsu or JCE Software.