Stable isotope Osmium (Os)

Isotope Z(p) N(n) Atomic Mass Natural Abundance Enrichment Level Chemical Form
Os-184 76 108 183.952491 0.02% ≥96.90% Metal
Os-186 76 110 185.953838 1.59% >99.00% Metal
Os-187 76 111 186.955748 1.96% >99.00% Metal
Os-188 76 112 187.955836 13.24% ≥94.00% Metal
Os-189 76 113 188.958145 16.15% >99.00% Metal
Os-190 76 114 189.958445 26.26% >99.00% Metal
Os-192 76 116 191.961479 40.78% >99.00% Metal
 

Properties of Osmium

Name Osmium
Symbol Os
Atomic number 76
Atomic weight 190.2
Standard state Solid at 298 ºK
CAS Registry ID 7440-04-2
Group in periodic table 8
Group name Precious metal or platinum group metal
Period in periodic table 6
Block in periodic table d-block
Color Bluish-gray
Classification Metallic
Melting point 3050 °C
Boiling point 5027 °C
Vaporization point 5300 ºC
Electrical resistivity 9.5 µΩ·cm at 20 ºC
Electronegativity 2.2
Specific heat 0.131 kJ/kg K at 20 ºC
Heat of vaporization 630 kJ·mol-1 at 5027 ºC
Heat of fusion 31 kJ·mol-1
Density of liquid 20 g/cm3 at 3050 °C
Density of solid 22.48 g/cm3
Electron configuration [Xe]4f145d66s2
Oxidation states +1, +2, +3, +4, +5, +6, +7, +8
Most common oxidation states +3, +4, +6
Moh’s hardness scale 7.0