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


Name Molybdenum Symbol Mo
atomic number 42 Atomic weight 95.94
Density @ 293 K 10.2 g/cm3 Atomic volume 9.4 cm3/mol
Group Trans. Met. discovered 1781


state (s, l, g) s
melting point 2890.2 K boiling point 4923 K
Heat of fusion 32.0 kJ/mol Heat of vaporization 598.0 kJ/mol
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1st ionization energy 684.9 kJ/mole electronegativity 2.24
2nd ionization energy 1588.2 kJ/mole electron affinity 72 kJ/mole
3rd ionization energy 2620.5 kJ/mole Specific heat 0.25 J/gK
heat atomization 658 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,13,1 electron configuration [Kr] 4d5 5s1
minimum oxidation number -2 maximum oxidation number 6
min. common oxidation no. 0 max. common oxidation no. 6
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Appearance & Characteristics

structure bcc: body-centered cubic color silvery-white
uses catalysts, tool steel toxicity
hardness mohs characteristics very hard


reaction with air none, w/ht = MoO3 reaction with 6M HCl none
reaction with 6M HCl none reaction with 15M HNO3
reaction with 6M NaOH
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Other Forms

number of isotopes 7 hydride(s) none
oxide(s) MoO2 MoO3 chloride(s) MoClx [x=2-6]


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 139 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) 83 pm
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thermal conductivity 138 J/m-sec-deg electrical conductivity 192.308 1/mohm-cm
polarizability 12.8 A^3


source Molybdenite (sulfide) rel. abund. solar system 0.407 log
abundance earth's crust 0.2 log cost, pure 11 $/100g
cost, bulk $/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.