Properties | More Info | Isotopes | Allotropes | Spectra
Compounds | Reactions | Production
Atomic: M.A.C. | Reference
Images | Video
Oxygen
Electron Configuration 2,6
Electron Configuration 1s2 2s2 2p4
Ground state 3P2
Atomic Volume 14 g/cm3
Electronegativity 3.44
Magnetic ordering Paramagnetic
Mass magnetic susceptibility 1.335 x 10-6
Molar magnetic susceptibility 2.13592 x 10-8
Speed of sound 330 m s-1
Thermal Properties
Enthalpy of Atomization 249.4 kJ mol-1 @25°C
Enthalpy of Fusion 0.444 kJ mol-1
Enthalpy of Vaporisation 6.82 kJ mol-1
Heat Capacity (O2) 29.378 J mol-1 K-1
Thermal Conductivity 26.58 W m-1 K-1
Thermal Expansion No data.
Electrical Properties
Electrical resistivity No data.
Electrical conductivity No data.
Chemical Properties
Electrochemical Equivalent 0.29847 g Ah-1
Valence Electron Potential (-eV) -20.6
Ionization Potential  
First 13.618
Second 35.117
Third 54.934
Incompatibilities Oxidizable materials.
Flammability
Non-flammable gas (Oxidizer)
Optical Properties
Refractive Index (gas) 1.000271
Energy Levels
Kα1 (intensity 100) 0.5249 KeV
Atomic Radii
Empirical 60 pm
Bohr Radius 48 pm
Covalent Radius 73 pm
Van der Waals 152 pm
Triple covalent 53 pm
Metallic No data.
Ionic Radii (Å)
Charge Coordination Crystal Ionic Key
-2  II 1.21 1.35
III 1.22 1.36
IV 1.24 1.38
VI 1.26 1.4
VIII 1.28 1.42
-1 (OH) II 1.18 1.32
III 1.2 1.34
IV 1.21 1.35 E
VI 1.23 1.37 E
R, From r3 vs V plots.
C, Calculated from bond length - bond strength equations.
E, Estimated.
*, Most Reliable.
M, From Metallic Oxides.
A, Ahrens (1952) Ionic radius.
P, Pauling's (1960) Crystal Radius.
Oxidation States
Main O-2
Other O-1, O0, O+1, O+2
Ionisation Energies (kJ mol-1) show graph
M - M+ 1313.9
M+ - M2+ 3388.2
M2+ - M3+ 5300.3
M3+ - M4+ 7469.1
M4+ - M5+ 10989.3
M5+ - M6+ 13326.2
M6+ - M7+ 71333.3
M7+ - M8+ 84076.3
Covalent Bonds (kJ mol-1)
146 O-O
498 O=O
200 O-N
360 O-C
743 O=C
Vapour Pressure
P (Pa) 1 10 100 1K 10K 100K
T (K) 61 73 90
Crystal Structure
Structure Monoclinic
a = 540.3 pm
b = 342.9 pm
c = 508.6 pm
α = 90°
β = 132.530°
γ = 90°