Oxygen

  • oxygen, 8o
    a transparent beaker containing a light blue fluid with gas bubbles
    liquid oxygen boiling
    oxygen
    allotropeso2, o3 (ozone)
    appearancegas: colorless
    liquid and solid: pale blue
    standard atomic weight ar, std(o)[15.9990315.99977] conventional: 15.999
    oxygen in the periodic table
    hydrogen helium
    lithium beryllium boron carbon nitrogen oxygen fluorine neon
    sodium magnesium aluminium silicon phosphorus sulfur chlorine argon
    potassium calcium scandium titanium vanadium chromium manganese iron cobalt nickel copper zinc gallium germanium arsenic selenium bromine krypton
    rubidium strontium yttrium zirconium niobium molybdenum technetium ruthenium rhodium palladium silver cadmium indium tin antimony tellurium iodine xenon
    caesium barium lanthanum cerium praseodymium neodymium promethium samarium europium gadolinium terbium dysprosium holmium erbium thulium ytterbium lutetium hafnium tantalum tungsten rhenium osmium iridium platinum gold mercury (element) thallium lead bismuth polonium astatine radon
    francium radium actinium thorium protactinium uranium neptunium plutonium americium curium berkelium californium einsteinium fermium mendelevium nobelium lawrencium rutherfordium dubnium seaborgium bohrium hassium meitnerium darmstadtium roentgenium copernicium nihonium flerovium moscovium livermorium tennessine oganesson


    o

    s
    nitrogenoxygenfluorine
    atomic number (z)8
    groupgroup 16 (chalcogens)
    periodperiod 2
    blockp-block
    element category  reactive nonmetal
    electron configuration[he] 2s2 2p4
    electrons per shell2, 6
    physical properties
    phase at stpgas
    melting point(o2) 54.36 k ​(−218.79 °c, ​−361.82 °f)
    boiling point(o2) 90.188 k ​(−182.962 °c, ​−297.332 °f)
    density (at stp)1.429 g/l
    when liquid (at b.p.)1.141 g/cm3
    triple point54.361 k, ​0.1463 kpa
    critical point154.581 k, 5.043 mpa
    heat of fusion(o2) 0.444 kj/mol
    heat of vaporization(o2) 6.82 kj/mol
    molar heat capacity(o2) 29.378 j/(mol·k)
    vapor pressure
    p (pa) 1 10 100 1 k 10 k 100 k
    at t (k)       61 73 90
    atomic properties
    oxidation states−2, −1, 0, +1, +2
    electronegativitypauling scale: 3.44
    ionization energies
    • 1st: 1313.9 kj/mol
    • 2nd: 3388.3 kj/mol
    • 3rd: 5300.5 kj/mol
    • (more)
    covalent radius66±2 pm
    van der waals radius152 pm
    color lines in a spectral range
    spectral lines of oxygen
    other properties
    natural occurrenceprimordial
    crystal structurecubic
    cubic crystal structure for oxygen
    speed of sound330 m/s (gas, at 27 °c)
    thermal conductivity26.58×10−3  w/(m·k)
    magnetic orderingparamagnetic
    magnetic susceptibility+3449.0·10−6 cm3/mol (293 k)[1]
    cas number7782-44-7
    history
    discoverycarl wilhelm scheele (1771)
    named byantoine lavoisier (1777)
    main isotopes of oxygen
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    16o 99.76% stable
    17o 0.04% stable
    18o 0.20% stable
    category category: oxygen
    | references

    oxygen is the chemical element with the symbol o and atomic number 8. it is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. by mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium. at standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula o
    2
    . diatomic oxygen gas constitutes 20.8% of the earth's atmosphere. as compounds including oxides, the element makes up almost half of the earth's crust.

    dioxygen is used in cellular respiration and many major classes of organic molecules in living organisms contain oxygen, such as proteins, nucleic acids, carbohydrates, and fats, as do the major constituent inorganic compounds of animal shells, teeth, and bone. most of the mass of living organisms is oxygen as a component of water, the major constituent of lifeforms. oxygen is continuously replenished in earth's atmosphere by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide. oxygen is too chemically reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. another form (allotrope) of oxygen, ozone (o
    3
    ), strongly absorbs ultraviolet uvb radiation and the high-altitude ozone layer helps protect the biosphere from ultraviolet radiation. however, ozone present at the surface is a byproduct of smog and thus a pollutant.

    oxygen was isolated by michael sendivogius before 1604, but it is commonly believed that the element was discovered independently by carl wilhelm scheele, in uppsala, in 1773 or earlier, and joseph priestley in wiltshire, in 1774. priority is often given for priestley because his work was published first. priestley, however, called oxygen "dephlogisticated air", and did not recognize it as a chemical element. the name oxygen was coined in 1777 by antoine lavoisier, who first recognized oxygen as a chemical element and correctly characterized the role it plays in combustion.

    common uses of oxygen include production of steel, plastics and textiles, brazing, welding and cutting of steels and other metals, rocket propellant, oxygen therapy, and life support systems in aircraft, submarines, spaceflight and diving.

  • history
  • characteristics
  • biological role of o2
  • industrial production
  • storage
  • applications
  • compounds
  • safety and precautions
  • see also
  • notes
  • references
  • external links

Oxygen, 8O
A transparent beaker containing a light blue fluid with gas bubbles
Liquid oxygen boiling
Oxygen
AllotropesO2, O3 (Ozone)
Appearancegas: colorless
liquid and solid: pale blue
Standard atomic weight Ar, std(O)[15.9990315.99977] conventional: 15.999
Oxygen in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson


O

S
nitrogenoxygenfluorine
Atomic number (Z)8
Groupgroup 16 (chalcogens)
Periodperiod 2
Blockp-block
Element category  Reactive nonmetal
Electron configuration[He] 2s2 2p4
Electrons per shell2, 6
Physical properties
Phase at STPgas
Melting point(O2) 54.36 K ​(−218.79 °C, ​−361.82 °F)
Boiling point(O2) 90.188 K ​(−182.962 °C, ​−297.332 °F)
Density (at STP)1.429 g/L
when liquid (at b.p.)1.141 g/cm3
Triple point54.361 K, ​0.1463 kPa
Critical point154.581 K, 5.043 MPa
Heat of fusion(O2) 0.444 kJ/mol
Heat of vaporization(O2) 6.82 kJ/mol
Molar heat capacity(O2) 29.378 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K)       61 73 90
Atomic properties
Oxidation states−2, −1, 0, +1, +2
ElectronegativityPauling scale: 3.44
Ionization energies
  • 1st: 1313.9 kJ/mol
  • 2nd: 3388.3 kJ/mol
  • 3rd: 5300.5 kJ/mol
  • (more)
Covalent radius66±2 pm
Van der Waals radius152 pm
Color lines in a spectral range
Spectral lines of oxygen
Other properties
Natural occurrenceprimordial
Crystal structurecubic
Cubic crystal structure for oxygen
Speed of sound330 m/s (gas, at 27 °C)
Thermal conductivity26.58×10−3  W/(m·K)
Magnetic orderingparamagnetic
Magnetic susceptibility+3449.0·10−6 cm3/mol (293 K)[1]
CAS Number7782-44-7
History
DiscoveryCarl Wilhelm Scheele (1771)
Named byAntoine Lavoisier (1777)
Main isotopes of oxygen
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
16O 99.76% stable
17O 0.04% stable
18O 0.20% stable
Category Category: Oxygen
| references

Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O
2
. Diatomic oxygen gas constitutes 20.8% of the Earth's atmosphere. As compounds including oxides, the element makes up almost half of the Earth's crust.

Dioxygen is used in cellular respiration and many major classes of organic molecules in living organisms contain oxygen, such as proteins, nucleic acids, carbohydrates, and fats, as do the major constituent inorganic compounds of animal shells, teeth, and bone. Most of the mass of living organisms is oxygen as a component of water, the major constituent of lifeforms. Oxygen is continuously replenished in Earth's atmosphere by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide. Oxygen is too chemically reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. Another form (allotrope) of oxygen, ozone (O
3
), strongly absorbs ultraviolet UVB radiation and the high-altitude ozone layer helps protect the biosphere from ultraviolet radiation. However, ozone present at the surface is a byproduct of smog and thus a pollutant.

Oxygen was isolated by Michael Sendivogius before 1604, but it is commonly believed that the element was discovered independently by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, and Joseph Priestley in Wiltshire, in 1774. Priority is often given for Priestley because his work was published first. Priestley, however, called oxygen "dephlogisticated air", and did not recognize it as a chemical element. The name oxygen was coined in 1777 by Antoine Lavoisier, who first recognized oxygen as a chemical element and correctly characterized the role it plays in combustion.

Common uses of oxygen include production of steel, plastics and textiles, brazing, welding and cutting of steels and other metals, rocket propellant, oxygen therapy, and life support systems in aircraft, submarines, spaceflight and diving.