Technical data for Osmium

Overview Name Osmium Symbol Os Atomic Number 76 Atomic Weight 190.23 Density 22.59 g/cm3 Melting Point 3033 °C Boiling Point 5012 °C Thermal properties Phase Solid Melting Point 3033 °C Boiling Point 5012 °C Absolute Melting Point 3306 K Absolute Boiling Point 5285 K Critical Pressure N/A Critical Temperature N/A Heat of Fusion 31 kJ/mol Heat of Vaporization 630 kJ/mol Specific Heat 130 J/(kg K)[note] Adiabatic Index N/A Neel Point N/A Thermal Conductivity 87 W/(m K) Thermal Expansion 5.1×10-6 K-1 Bulk physical properties Density 22.59 g/cm3 Density (Liquid) 20 g/cm3 Molar Volume 8.421×10-6 Brinell Hardness 3920 MPa Mohs Hardness 7 Vickers Hardness 4137.063913415 MPa[note] Bulk Modulus N/A Shear Modulus 222 GPa Young Modulus N/A Poisson Ratio 0.25 Refractive Index N/A Speed of Sound 4940 m/s Thermal Conductivity 87 W/(m K) Thermal Expansion 5.1×10-6 K-1 Reactivity Valence 6 Electronegativity 2.2 ElectronAffinity 106.1 kJ/mol Ionization Energies 840, 1600 kJ/mol Health and Safety DOT Hazard Class 4.1 DOT Numbers 3089 RTECS Number RTECSRN1100000 NFPA Label

Classifications Alternate Names None Names of Allotropes None Block d Group 8 Period 6 Series Transition Metal Electron Configuration [Xe]6s24f145d6 Color SlateGray Discovery 1803 in The United Kingdom Gas phase N/A CAS Number CAS7440-04-2 CID Number CID23937 RTECS Number RTECSRN1100000 Electrical properties Electrical Type Conductor Electrical Conductivity 1.2×107 S/m Resistivity 8.000000000001×10-8 m Ω Superconducting Point 0.66 Magnetic properties Magnetic Type Paramagnetic Curie Point N/A Mass Magnetic Susceptibility 6×10-10 m3/Kg Molar Magnetic Susceptibility 1.1×10-10 m3/mol Volume Magnetic Susceptibility 0.000014 Abundances % in Universe 3×10-7% % in Sun 2×10-7% % in Meteorites 0.000065% % in Earth's Crust 1.8×10-7% % in Oceans N/A % in Humans N/A Atomic dimensions and structure Atomic Radius 185 pm Covalent Radius 144 pm Van der Waals Radius N/A Crystal Structure Simple Hexagonal Lattice Angles π/2, π/2, 2 π/3 Lattice Constants 273.44, 273.44, 431.73 pm Space Group Name P63/mmc Space Group Number 194 Nuclear Properties Half-Life Stable Lifetime Stable Decay Mode N/A Quantum Numbers 5D4 Neutron Cross Section 15 Neutron Mass Absorption 0.0023 Known Isotopes 162Os, 163Os, 164Os, 165Os, 166Os, 167Os, 168Os, 169Os, 170Os, 171Os, 172Os, 173Os, 174Os, 175Os, 176Os, 177Os, 178Os, 179Os, 180Os, 181Os, 182Os, 183Os, 184Os, 185Os, 186Os, 187Os, 188Os, 189Os, 190Os, 191Os, 192Os, 193Os, 194Os, 195Os, 196Os Stable Isotopes 184Os, 187Os, 188Os, 189Os, 190Os, 192Os Isotopic Abundances 184Os 0.02% 186Os 1.59% 187Os 1.96% 188Os 13.24% 189Os 16.15% 190Os 26.26% 192Os 40.78%