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


Name Osmium Symbol Os
atomic number 76 Atomic weight 190.2
Density @ 293 K 22.40 g/cm3 Atomic volume 8.49 cm3/mol
Group Trans. Met. discovered 1804


state (s, l, g) s
melting point 3318.2 K boiling point 5298 K
Heat of fusion 31.80 kJ/mol Heat of vaporization 746.0 kJ/mol
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1st ionization energy 840 kJ/mole electronegativity 2.2
2nd ionization energy kJ/mole electron affinity 110 kJ/mole
3rd ionization energy kJ/mole Specific heat 0.13 J/gK
heat atomization 791 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,32,14,2 electron configuration [Xe] 4f14 5d6 6s2
minimum oxidation number -2 maximum oxidation number 8
min. common oxidation no. 0 max. common oxidation no. 4
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Appearance & Characteristics

structure hcp: hexagonal close pkd color bluish-white
uses hard alloys,phono needles toxicity
hardness 7 mohs characteristics hard, dense, inert <100 /td c>


reaction with air none reaction with 6M HCl none
reaction with 6M HCl none reaction with 15M HNO3 mild, = OsO4
reaction with 6M NaOH
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Other Forms

number of isotopes 7 hydride(s) none
oxide(s) OsO2 OsO4 chloride(s) OsCl3 OsCl4 OsCl5


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 135 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) pm
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thermal conductivity 87.6 J/m-sec-deg electrical conductivity 105.263 1/mohm-cm
polarizability 8.5 A^3


source nickel ores (sulfides) rel. abund. solar system -0.171 log
abundance earth's crust -2.8 log cost, pure 7700 $/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.