OXYGEN

Symbol --- O

Abundance --- most abundant element, 46% in the earth’s crust, 21% by volume in air, 89% by weight of the water in the oceans.

Allotropes --- atomic oxygen [O(³P)], dioxygen (O₂), ozone (O₃), tetraoxygen (O₄), solid oxygen.

Physical state --- gas

Colour --- colourless gas

Discovery --- C W Scheele

Atomic no --- 8

Atomic weight --- 15.999

Period --- 2

Group --- 16 or VIA

Block --- p block

Known isotopes --- ₈O¹², ₈O¹³, ₈O¹⁴, ₈O¹⁵, ₈O¹⁶, ₈O¹⁷, ₈O¹⁸, ₈O¹⁹, ₈O²⁰, ₈O²¹, ₈O²², ₈O²³, ₈O²⁴

Main isotopes --- ₈O¹⁶, ₈O¹⁷, ₈O¹⁸

Isotopic abundance --- ₈O¹⁶ (99.763%), ₈O¹⁷ (0.037%), ₈O¹⁸ (0.2%)

Melting Point --- - 219 ⁰C (54 K) (dioxygen)

Boiling Point --- - 183 ⁰C (90 K) (dioxygen)

Triple Point --- 54 K, 0.14 kPa

Critical Temperature --- 154 K

Critical Pressure --- 5.04 MPa

Heat of Fusion --- 0.44 KJ/mol (dioxygen)

Heat of Vaporisation --- 6.81 KJ/mol (dioxygen)

ΔH⁰_{(atomization)} --- 247 KJ/mol

Molar heat capacity --- 29.37 J/(mol-K) (dioxygen)

Density --- 1.41 g/L (at STP)

Molar volume --- 0.0111

Electron configuration --- [He] 2s² 2p⁴

Electrons per shell --- 2 (1 st shell), 6 (2 nd shell)

Oxidation state --- -2, -1

Valance --- 2

Electronegativity --- 3.44 (Pauling scale)

Electron affinity --- 1.41 KJ/mol

Ionisation energy --- 1314 KJ/mol (1 st), 3388 KJ/mol (2 nd), 5300.3 KJ/mol (3 rd), 7469.1 KJ/mol (4 th)

Covalent radius --- 66 pm

Van der Waals radius --- 152 pm

Atomic radius --- 48 pm

Natural occurrence --- primordial

Crystal structure --- cubic

Specific heat --- 918.5 J/(Kg K) (gas)

Thermal conductivity --- 0.026 W/(m K)

Speed of sound --- 330 m/s (gas)

Magnetic type --- paramagnetic

Mass magnetic susceptibility --- 1.33 x 10^-6 m³/Kg

Molar magnetic susceptibility --- 4.27 x 10^-8 m³/mol

Volume magnetic susceptibility --- 1.9 x 10^-6

Lattice angles --- π/2, 2.31, π/2

Lattice constants --- 540.1 pm, 342.8 pm, 508.5 pm

Quantum numbers --- ³P₂

Neutron cross section --- 2.8 x 10^-4

Neutron mass absorption --- 1 x 10^-6

Refractive index --- 1.0002