Oxygen (O)
A colourless, odourless gaseous element belonging to group 16 of the periodic table. It is the most abundant element present in the earth's crust. It also makes up 20.8% of the Earth's atmosphere. For industrial purposes, it is separated from liquid air by fractional distillation. It is used in high temperature welding, and in breathing. It commonly comes in the form of Oxygen, but is found as Ozone in the upper atmosphere. It was discovered by Priestley in 1774.
| Atomic Number | 8 |
|---|---|
| Atomic Weight | 15.999 |
| Mass Number | 16 |
| Group | 16 |
|---|---|
| Period | 2 |
| Block | p |
| Protons | 8 p+ |
|---|---|
| Neutrons | 8 n0 |
| Electrons | 8 e- |
Properties
| Atomic Radius | 60 pm
|
|---|---|
| Atomic Volume | 14 cm³/mol
|
| Covalent Radius | 63 pm
|
| Metallic Radius | |
| Ionic Radius | 135 pm
|
| Crystal Radius | 121 pm
|
| Van der Waals radius |
152 pm
|
| Density | 0.001308 g/cm³
|
| Boiling Point | 90.19 K
|
| Melting Point | 54.8 K
|
| Electrons per shell | 2, 6 |
| Electronegativity |
3.44
|
| Electrophilicity | 2.3379781748238 eV/particle
|
| Proton Affinity | 485.2 kJ/mol
|
| Electron Affinity | 1.4611135 eV/particle
|
| Ionization Potential | 13.618054 eV/particle
|
| Heat of Vaporization | |
| Heat of Fusion | |
| Heat of Formation | 249.229 kJ/mol
|
| Molar Heat Capacity | 29.378 J/(mol K)
|
| Specific Heat Capacity | 0.918 J/(g⋅K)
|
| Thermal Conductivity | 0.027 W/(m K)
|
| Gas Basicity | 459.6 kJ/mol
|
| Dipole Polarizability | 5.3 a₀
|
| C6 Dispersion Coefficient | 15.6 a₀
|
| Oxidation States | -2, -1, 1, 2 |
| Color | Colorless
|
| Crystal Structure | Base Centered Monoclinic (CUB) |
| Lattice Constant | 6.83 Å
|
| Bulk Modulus | |
| Electrical Resistivity | |
| Electron Configuration | [He] 2s2 2p4 |
| Magnetic Ordering | |
| Magnetic Susceptibility | |
| Phase | Gas |
| Poisson Ratio | |
| Shear Modulus | |
| Young's Modulus | |
| Allotropes | |
| Alternate Names | |
| Adiabatic Index | |
| Appearance | |
| Electric Conductivity | |
| Critical Pressure | |
| Critical Temperature | |
| Curie Point | |
| Electrical | |
| Hardness | |
| Magnetic Susceptibility | |
| Magnetic | |
| Neel Point | |
| Neutron Cross Section | |
| Neutron Mass Absorption | |
| Gas Phase | |
| Quantum Numbers | |
| Refractive Index | |
| Space Group | |
| Speed of Sound | |
| Superconducting Point | |
| Thermal Expansion | |
| Valence Electrons | |
| Classification | |
| Category | Other nonmetals, Nonmetals |
| CAS Group | VIB |
| IUPAC Group | VIA |
| Glawe Number | 97 |
| Mendeleev Number | 99 |
| Pettifor Number | 101 |
| Geochemical Class | major |
| Goldschmidt Class | litophile |
| Radioactivity | |
| Radioactive | No |
| Decay Mode | |
| Half-Life | |
| Lifetime | |
| Abundance | |
| Abundance in Earth's crust | 461,000 mg/kg
|
| Abundance in Oceans | 857,000 mg/L
|
| Abundance in Human Body | |
| Abundance in Meteor | |
| Abundance in Sun | |
| Abundance in Universe | 1% |
Isotopes of Oxygen
Stable Isotopes
16O 17O 18O
Unstable Isotopes
12O 13O 14O 15O 19O 20O 21O 22O 23O 24O 25O 26O 27O 28O
History
Carl Wilhelm Scheele obtained oxygen by heating mercuric oxide and nitrates in 1771, but did not publish his findings until 1777. Joseph Priestley also prepared this new air by 1774. The name oxygen was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion. From the Greek word oxys, acid, and genes, forming
| Discoverers | Joseph Priestly, Carl Wilhelm Scheele |
|---|---|
| Discovery Location | England/Sweden |
| Discovery Year | 1774 |
| Name Origin | Greek: oxys and genes, (acid former). |
Oxygen gas can be toxic at elevated partial pressures, leading to convulsions and other health problems
Green and red colors in the Aurora Borealis are caused by oxygen atoms
Uses
Pure oxygen is frequently used to help breathing in patients with respiratory ailments. Oxygen is used in oxyacetylene welding, as an oxidant for rocket fuel, and in methanol and ethylene oxide production. It is also used in the production of steel, plastics and textiles. Plants and animals rely on oxygen for respiration. Used in steel making, welding, and supporting life. Naturally occuring ozone (O3) in the upper atmosphere shields the earth from ultraviolet radiation.
Sources
Obtained primarily from liquid air by fractional distillation. Small amounts are made in the laboratory by electrolysis of water or heating potassium chlorate (KClO3) with manganese dioxide (MnO2) catalyst.