Technical data for Oxygen

Overview Name Oxygen Symbol O Atomic Number 8 Atomic Weight 15.999 Density 1.429 g/l[note] Melting Point -218.3 °C Boiling Point -182.9 °C Thermal properties Phase Gas Melting Point -218.3 °C Boiling Point -182.9 °C Absolute Melting Point 54.8 K Absolute Boiling Point 90.2 K Critical Pressure 5.043 MPa (49.77 Atm) Critical Temperature 154.59 K Heat of Fusion 0.222 kJ/mol Heat of Vaporization 3.41 kJ/mol Specific Heat 919 J/(kg K)[note] Adiabatic Index 7/5 Neel Point N/A Thermal Conductivity 0.02658 W/(m K) Thermal Expansion N/A Bulk physical properties Density 1.429 g/l[note] Density (Liquid) N/A Molar Volume 0.011196 Brinell Hardness N/A Mohs Hardness N/A Vickers Hardness N/A Bulk Modulus N/A Shear Modulus N/A Young Modulus N/A Poisson Ratio N/A Refractive Index 1.000271 Speed of Sound 317.5 m/s Thermal Conductivity 0.02658 W/(m K) Thermal Expansion N/A Reactivity Valence 2 Electronegativity 3.44 ElectronAffinity 141 kJ/mol Ionization Energies 1313.9, 3388.3, 5300.5, 7469.2, 10989.5, 13326.5, 71330, 84078 kJ/mol Health and Safety DOT Hazard Class 2.2 DOT Numbers 1073 RTECS Number RTECSRS2060000 NFPA Label

Classifications Alternate Names None Names of Allotropes Dioxygen, Ozone, Tetraoxygen Block p Group 16 Period 2 Series Chalcogen Electron Configuration [He]2s22p4 Color Colorless Discovery 1774 in Sweden and The United Kingdom Gas phase Diatomic CAS Number CAS7782-44-7 CID Number CID977 RTECS Number RTECSRS2060000 Electrical properties Electrical Type N/A Electrical Conductivity N/A Resistivity N/A Superconducting Point N/A Magnetic properties Magnetic Type Paramagnetic Curie Point N/A Mass Magnetic Susceptibility 1.335×10-6 m3/Kg Molar Magnetic Susceptibility 4.27184×10-8 m3/mol Volume Magnetic Susceptibility 1.90772×10-6 Abundances % in Universe 1% % in Sun 0.9% % in Meteorites 40% % in Earth's Crust 46% % in Oceans 86% % in Humans 61% Atomic dimensions and structure Atomic Radius 48 pm Covalent Radius 66 pm Van der Waals Radius 152 pm Crystal Structure Base-centered Monoclinic Lattice Angles π/2, 2.313085, π/2 Lattice Constants 540.3, 342.9, 508.6 pm Space Group Name C12/m1 Space Group Number 12 Nuclear Properties Half-Life Stable Lifetime Stable Decay Mode N/A Quantum Numbers 3P2 Neutron Cross Section 0.00028 Neutron Mass Absorption 1×10-6 Known Isotopes 12O, 13O, 14O, 15O, 16O, 17O, 18O, 19O, 20O, 21O, 22O, 23O, 24O, 25O, 26O, 27O, 28O Stable Isotopes 16O, 17O, 18O Isotopic Abundances 16O 99.757% 17O 0.038% 18O 0.205%