Frae Wikipedia
Lowp tae: navigation, rake
Oxygen,  8O
A transparent beaker conteenin a light blue fluid wi gas bubbles
Liquid oxygen bylin
General properties
Appearance gas: colourless
liquid: pale blue
Staundart atomic wecht (Ar, staundart) [15.9990315.99977] conventional: 15.999[1]
Oxygen in the periodic cairt
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 Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) 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 Mercur (element) Thallium Leid (element) 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 Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium


Atomic nummer (Z) 8
Group group 16 (chalcogens)
Period period 2
Element category   diatomic nonmetal
Block p-block
Electron confeeguration [He] 2s2 2p4
Electrons per shell
2, 6
Pheesical properties
Phase (at STP) gas
Meltin pynt 54.36 K ​(−218.79 °C, ​−361.82 °F)
Bylin pynt 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
Treeple pynt 54.361 K, ​0.1463 kPa
Creetical pynt 154.581 K, 5.043 MPa
Heat o fusion (O2) 0.444 kJ/mol
Heat o vapourisation (O2) 6.82 kJ/mol
Molar heat capacity (O2) 29.378 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K)       61 73 90
Atomic properties
Oxidation states 2, 1, −1, −2
Electronegativity Pauling scale: 3.44
Ionisation energies
  • 1st: 1313.9 kJ/mol
  • 2nd: 3388.3 kJ/mol
  • 3rd: 5300.5 kJ/mol
  • (more)
Covalent radius 66±2 pm
Van der Waals radius 152 pm
Color lines in a spectral range
Creestal structur cubic
Cubic creestal structur for oxygen
Speed o soond 330 m/s (gas, at 27 °C)
Thermal conductivity 26.58×10−3  W/(m·K)
Magnetic orderin paramagnetic
Magnetic susceptibility +3449.0·10−6 cm3/mol (293 K)[2]
CAS Nummer 7782-44-7
Diskivery Carl Wilhelm Scheele (1771)
Named bi Antoine Lavoisier (1777)
Main isotopes o oxygen
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
16O 99.76% stable
17O 0.04% stable
18O 0.20% stable
| references | in Wikidata

Oxygen is a chemical element wi seembol O an atomic nummer 8. It is a member o the chalcogen group on the periodic cairt an is a heichly reactive nonmetal an oxidisin agent that readily forms oxides wi maist elements as well as ither compoonds.[3] Bi mass, oxygen is the third-maist abundant element in the universe, efter hydrogen an helium.[4] At staundart temperatur an pressur, twa atoms o the element bind tae form dioxygen, a colourless an odourless diatomic gas wi the formula O
. This is an important pairt o the atmosphere an diatomic oxygen gas constitutes 20.8% o the Yird's atmosphere.[5] Addeetionally, as oxides the element maks up awmaist hauf o the Yird's crust.[6]

Dioxygen is uised in cellular respiration an mony major classes o organic molecules in livin organisms conteen oxygen, sic as proteins, nucleic acids, carbohydrates, an fats, as dae the major consteetuent inorganic compoonds o ainimal shells, teeth, an bane. Maist o the mass o livin organisms is oxygen as a component o watter, the major constituent o lifeforms. Conversely, oxygen is continuously replenished bi photosynthesis, which uises the energy o sunlicht tae produce oxygen frae watter an carbon dioxide. Oxygen is ower chemically reactive tae remeen a free element in air withoot bein continuously replenished bi the photosynthetic action o livin organisms. Anither form (allotrope) o oxygen, ozone (O
), strangly absorbs ultraviolet UVB radiation an the heich-altitude ozone layer helps pertect the biosphere frae ultraviolet radiation. But ozone is a pollutant near the surface whaur it is a bi-product o smog. At law yird orbit altitudes, sufficient atomic oxygen is present tae cause corrosion o spacecraft.[7]

Oxygen wis discovered independently bi Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, an Joseph Priestley in Wiltshire, in 1774, but Priestley is eften gien priority acause his wark wis published first. The name oxygen wis coined in 1777 bi Antoine Lavoisier,[8] whase experiments wi oxygen helped tae discredit the then-popular phlogiston theory o combustion an corrosion. Its name derives frae the Greek roots ὀξύς oxys, "acid", leeterally "sharp", referrin tae the soor taste o acids an -γενής -genes, "producer", leeterally "begetter", acause at the time o namin, it wis mistakenly thocht that aw acids required oxygen in thair composeetion.

Common uise o oxygen includes residential heatin, internal combustion ingines, production o steel, plastics an textiles, brazin, waldin an cuttin o steels an ither metals, rocket propellant, oxygen therapy, an life support seestems in aircraft, submarines, spaceflicht an divin.

References[eedit | eedit soorce]

  1. Meija, J.; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305. 
  2. Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4. 
  3. "WebElements: the periodic table on the web – Oxygen: electronegativities". WebElements.com. Retrieved November 7, 2011. 
  4. Emsley 2001, p.297
  5. Cook & Lauer 1968, p.500
  6. "Oxygen". Los Alamos National Laboratory. Archived frae the oreeginal on October 26, 2007. Retrieved December 16, 2007. 
  7. "Atomic oxygen erosion". Archived frae the oreeginal on Juin 13, 2007. Retrieved August 8, 2009. 
  8. Parks, G. D.; Mellor, J. W. (1939). Mellor's Modern Inorganic Chemistry (6th ed.). London: Longmans, Green and Co.