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
Biologists discover bacterial defense mechanism against aggressive oxygen
Nov 20, 2009 |
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Bacteria possess an ingenious mechanism for preventing oxygen from harming the building blocks of the cell. This is the new finding of a team of biologists that includes Joris Messens of VIB, a life sciences research institute ...
Students with a lower socioeconomic background benefit from daily school physical activity
Nov 17, 2009 |
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German school students -- especially those with low socioeconomic status (SES) -- significantly improved their exercise capacity and body leanness after a year of daily physical activity classes, according to research presented ...
Earth's early ocean cooled more than a billion years earlier than thought (w/ Video)
Space & Earth / Earth Sciences
Nov 11, 2009 |
4.3 / 5 (12) |
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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 ...
When seconds count: Interventional radiology treatment for pulmonary embolism saves lives
Nov 11, 2009 |
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Catheter-directed therapy or catheter-directed thrombolysis -- an interventional radiology treatment that uses targeted image-guided drug delivery with specially designed catheters to dissolve dangerous blood clots in the ...
Pathogen protection and virulence: Dark side of fungal membrane protein revealed
Nov 06, 2009 |
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Researchers at the Virginia Bioinformatics Institute (VBI) at Virginia Tech and Montana State University have discovered a fungal protein that plays a key role in causing disease in plants and animals and which also shields ...
Hybrid molecules show promise for exploring, treating Alzheimer's
Nov 04, 2009 |
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One of the many mysteries of Alzheimer's disease is how protein-like snippets called amyloid-beta peptides, which clump together to form plaques in the brain, may cause cell death, leading to the disease's devastating symptoms ...
Computer Science Provides a More Sound Way to Test for Sleep Apnea
Nov 02, 2009 |
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(PhysOrg.com) -- A computer scientist from the University of Houston and a doctor of sleep medicine at the University of Texas Health Science Center at Houston have teamed up to create a new, less invasive ...
Inhibitor of Heat Shock Protein is a Potential Anticancer Drug, Study Finds
Oct 29, 2009 |
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(PhysOrg.com) -- Like yoga for office drones, cells do have coping strategies for stress. Heat, lack of nutrients, oxygen radicals - all can wreak havoc on the delicate internal components of a cell, potentially ...
Ancient ocean chemistry: Effects of biological oxygen production 100 million years before it accumulated in atmosphere
Space & Earth / Earth Sciences
Oct 29, 2009 |
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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 ...
Snail fossils suggest semiarid eastern Canary Islands were wetter 50,000 years ago
Space & Earth / Earth Sciences
Oct 27, 2009 |
2.5 / 5 (2) |
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Fossil land snail shells found in ancient soils on the subtropical eastern Canary Islands show that the Spanish archipelago off the northwest coast of Africa has become progressively drier over the past 50,000 years.
Like a hungry teen, life on Earth had big growth spurts
Space & Earth / Earth Sciences
Oct 27, 2009 |
3.6 / 5 (7) |
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Twice in the Earth's history, living creatures underwent astonishing growth spurts, and each time, new organisms emerged that were a million times larger than anything that had existed before.
PhD student solves decade-long mystery of magnetism
Oct 27, 2009 |
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(PhysOrg.com) -- A PhD student from the London Centre for Nanotechnology has won a prize for solving a decade-long mystery central to understanding modern magnetic systems.
Sensor biochips could aid in cancer diagnosis and treatment
Chemistry / Analytical Chemistry
Oct 22, 2009 |
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It is very difficult to predict whether a cancer drug will help an individual patient: only around one third of drugs will work directly in a given patient. Researchers at the Heinz Nixdorf Chair for Medical ...
Study: Added oxygen during stroke reduces brain tissue damage
Medicine & Health / Neuroscience
Oct 19, 2009 |
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Scientists have countered findings of previous clinical trials by showing that giving supplemental oxygen to animals during a stroke can reduce damage to brain tissue surrounding the clot.
Cargo craft docks with space station
Space & Earth / Space Exploration
Oct 18, 2009 |
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(AP) -- A cargo ship has delivered food, fuel, oxygen and other supplies to the International Space Station.
