Other

Strawberries protect the stomach from alcohol

In an experiment on rats, European researchers have proved that eating strawberries reduces the harm that alcohol can cause to the stomach mucous membrane. Published in the open access journal Plos One, the study may contribute ...

Health

New recommendations in bedsharing debate

Researchers from Murdoch University's School of Health Professions are urging health organisations to reconsider their attitudes to mothers and babies bedsharing.

Psychology & Psychiatry

Brain study connects cannabis, oxygen changes

New research from the Center for BrainHealth at The University of Texas at Dallas reveals that levels of THC, the psychoactive ingredient in cannabis that leaves a euphoric feeling, directly correlate to changes in how the ...

Medical research

Mystery of resistance to malaria solved in new study

(Medical Xpress) -- Malaria is a disease caused by parasites passed to humans via the bites of infected mosquitoes. Globally, the disease causes over a million deaths every year, and is especially rife in parts of Africa ...

Diseases, Conditions, Syndromes

Hyperbaric hope for fibromyalgia sufferers

Women who suffer from fibromyalgia benefit from a treatment regimen in a hyperbaric oxygen chamber, according to researchers at Rice University and institutes in Israel.

page 1 from 100

Oxygen

Oxygen (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.

This text uses material from Wikipedia, licensed under CC BY-SA