Oxygen
hideOxygen (pronounced /ˈɒksɨdʒɨn/, from the Greek roots ὀξύς (oxys) (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter) is the element with atomic number 8 and represented by the symbol O. It is a member of the chalcogen group on the periodic table, and is a highly reactive nonmetallic period 2 element that readily forms compounds (notably oxides) with almost all other elements. At standard temperature and pressure two atoms of the element bind to form dioxygen, a colorless, odorless, tasteless diatomic gas with the formula O2. Oxygen is the third most abundant element in the universe by mass after hydrogen and helium and the most abundant element by mass in the Earth's crust. Diatomic oxygen gas constitutes 20.9% of the volume of air.
All major classes of structural molecules in living organisms, such as proteins, carbohydrates, and fats, contain oxygen, as do the major inorganic compounds that comprise animal shells, teeth, and bone. Oxygen in the form of O2 is produced from water by cyanobacteria, algae and plants during photosynthesis and is used in cellular respiration for all complex life. Oxygen is toxic to obligately anaerobic organisms, which were the dominant form of early life on Earth until O2 began to accumulate in the atmosphere 2.5 billion years ago. Another form (allotrope) of oxygen, ozone (O3), helps protect the biosphere from ultraviolet radiation with the high-altitude ozone layer, but is a pollutant near the surface where it is a by-product of smog. At even higher low earth orbit altitudes monatomic oxygen (O1) is a significant presence and a cause of erosion for spacecraft.
Oxygen was independently discovered by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, and Joseph Priestley in Wiltshire, in 1774, but Priestley is often given priority because his publication came out in print first. 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. Oxygen is produced industrially by fractional distillation of liquefied air, use of zeolites to remove carbon dioxide and nitrogen from air, electrolysis of water and other means. Uses of oxygen include the production of steel, plastics and textiles; rocket propellant; oxygen therapy; and life support in aircraft, submarines, spaceflight and diving.
For more information about Oxygen, read the full article at
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News tagged with oxygen
Machine Converts CO2 into Gasoline, Diesel, and Jet Fuel
Nov 23, 2009 |
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(PhysOrg.com) -- Researchers at Sandia National Laboratories have built a machine that uses the sun's energy to convert carbon dioxide waste from power plants into transportation fuels such as gasoline, diesel, ...
Earth's early ocean cooled more than a billion years earlier than thought (w/ Video)
Space & Earth / Earth Sciences
Nov 11, 2009 |
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(PhysOrg.com) -- The scalding-hot sea that supposedly covered the early Earth may in fact never have existed, according to a new study by Stanford University researchers who analyzed isotope ratios in 3.4 ...
Ancient ocean chemistry: Effects of biological oxygen production 100 million years before it accumulated in atmosphere
Space & Earth / Earth Sciences
Oct 29, 2009 |
4.8 / 5 (13) |
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(PhysOrg.com) -- Scientists widely accept that around 2.4 billion years ago, the Earth's atmosphere underwent a dramatic change when oxygen levels rose sharply. Called the "Great Oxidation Event" (GOE), the ...
Jupiter's Moon Europa Has Enough Oxygen For Life
Space & Earth / Earth Sciences
Oct 16, 2009 |
4.8 / 5 (94) |
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New research suggests that there is plenty of oxygen available in the subsurface ocean of Europa to support oxygen-based metabolic processes for life similar to that on Earth. In fact, there may be enough ...
US army to be powered by waste
Oct 12, 2009 |
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(PhysOrg.com) -- Defense company Qinetiq has been awarded a contract to supply the US army with a system that generates electricity from garbage.
Oxygen in place of chlorine: Towards a more environmentally friendly propylene oxide synthesis
Nanotechnology / Nanomaterials
Oct 01, 2009 |
4.8 / 5 (4) |
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(PhysOrg.com) -- Propylene oxide is an important bulk chemical that is used primarily in the production of polyurethane plastics. Currently, propylene oxide is usually made from propylene (propene) in a process that uses ...
Hydrogen-making algae's 'Achilles' heel' discovered
Sep 29, 2009 |
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(PhysOrg.com) -- Scientists have discovered how oxygen stops green algae from producing hydrogen. The findings could help those working towards 'solar H2-farms' in which microorganisms produce hydrogen fuel ...
Cockroaches Control Their Breathing to Save Water
Sep 24, 2009 |
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(PhysOrg.com) -- Many insects have been known for decades to hold their breath when resting, but the reasons have not been well understood. A new study on cockroaches suggests the insects reduce their breathing ...
Ancient oceans offer new insight into the origins of animal life
Space & Earth / Earth Sciences
Sep 09, 2009 |
4.4 / 5 (10) |
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(PhysOrg.com) -- Analysis of a rock type found only in the world's oldest oceans has shed new light on how large animals first got a foothold on the Earth.
Ozone: Climate change boosts ultraviolet risk for high latitudes
Space & Earth / Earth Sciences
Sep 06, 2009 |
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(PhysOrg.com) -- Physicists at the University of Toronto have discovered that changes in the Earth's ozone layer due to climate change will reduce the amount of ultraviolet (UV) radiation in northern high ...
Scientists Make Oxygen Out of Moon Rock
Space & Earth / Space Exploration
Aug 11, 2009 |
4.6 / 5 (27) |
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(PhysOrg.com) -- If humans ever create a lunar base, one of the biggest challenges will be figuring out how to breathe. Transporting oxygen to the moon is extremely expensive, so for the past several years ...
Beetroot juice boosts stamina, new study shows
Aug 06, 2009 |
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(PhysOrg.com) -- Drinking beetroot juice boosts your stamina and could help you exercise for up to 16% longer. A University of Exeter led-study, published today, shows for the first time how the nitrate contained ...
Explosive growth of life on Earth fueled by early greening of planet
Space & Earth / Earth Sciences
Jul 08, 2009 |
4.7 / 5 (10) |
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Earth's 4.5-billion-year history is filled with several turning points when temperatures changed dramatically, asteroids bombarded the planet and life forms came and disappeared. But one of the biggest moments ...
53 million-year-old high Arctic mammals wintered in darkness
Space & Earth / Earth Sciences
Jun 01, 2009 |
4.8 / 5 (17) |
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(PhysOrg.com) -- Ancestors of tapirs and ancient cousins of rhinos living above the Arctic Circle 53 million years ago endured six months of darkness each year in a far milder climate than today that featured ...
The rise of oxygen caused Earth's earliest ice age
Space & Earth / Earth Sciences
May 07, 2009 |
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(PhysOrg.com) -- Geologists may have uncovered the answer to an age-old question - an ice-age-old question, that is. It appears that Earth's earliest ice ages may have been due to the rise of oxygen in Earth's ...
