Chemicool

Os

76

190.2
Osmium
General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles

General
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

States
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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Energies
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>

Reactions
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

Radius
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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Conductivity
thermal conductivity 87.6 J/m-sec-deg electrical conductivity 105.263 1/mohm-cm
polarizability 8.5 A^3

Abundance
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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