Oxygen - Isotopes

Oxygen is a chemical element in the periodic table. It has the symbol O and atomic number 8. The element is very common, found not only on Earth but throughout the universe, usually covalently bonded with other elements. Unbound oxygen (usually called molecular oxygen, O2, a diatomic molecule) first appeared on Earth during the Paleoproterozoic era (between 2500 million years ago and 1600 million years ago) and as a product of the metabolic action of early anaerobes (archaea and bacteria). The presence of free oxygen ...

Including:

• Oxygen - Characteristics
• Oxygen - Applications
• Oxygen - History
• Oxygen - Occurrence
• Oxygen - Compounds
• Oxygen - Isotopes
• Oxygen - Precautions

Read more here: » Oxygen: Encyclopedia - Oxygen

At standard temperature and pressure, oxygen exists as a diatomic molecule with the formula O2, in which the two oxygen atoms are doubly bonded to each other. In its most stable form, oxygen exists as a diradical (triplet oxygen). Though radicals are commonly associated with highly reactive compounds, triplet oxygen is surprisingly (and fortunately) unreactive towards most compounds. Singlet oxygen, a name given to several higher energy species in which all the electron spins are paired, is much more ...

See also:

Oxygen, Oxygen - Characteristics, Oxygen - Applications, Oxygen - History, Oxygen - Occurrence, Oxygen - Compounds, Oxygen - Isotopes, Oxygen - Precautions

Read more here: » Oxygen: Encyclopedia II - Oxygen - Characteristics

Oxygen can be toxic at elevated partial pressures (i.e. high relative concentrations). This is important in some forms of scuba diving, such as with a rebreather. Certain derivatives of oxygen, such as ozone (O3), singlet oxygen, hydrogen peroxide, hydroxyl radicals and superoxide, are also highly toxic. The body has developed mechanisms to protect against these toxic species. For instance, the naturally-occurring glutathione can act as an antioxidant, as can bilirubin which is normally a breakdown product of hemoglobin. To ...

See also:

Oxygen, Oxygen - Characteristics, Oxygen - Applications, Oxygen - History, Oxygen - Occurrence, Oxygen - Compounds, Oxygen - Isotopes, Oxygen - Precautions

Read more here: » Oxygen: Encyclopedia II - Oxygen - Precautions

Liquid oxygen finds use as an oxidizer in rocket propulsion. Oxygen is essential to respiration, so oxygen supplementation has found use in medicine (as oxygen therapy). People who climb mountains or fly in airplanes sometimes have supplemental oxygen supplies (as air). Oxygen is used in welding (such as the oxyacetylene torch), and in the making of steel and methanol. Oxygen presents two absorption bands centered in the wavelengths 687 and 760 nanometers. Some scientists have proposed to use the measurement of the radiance coming fro ...

See also:

Oxygen, Oxygen - Characteristics, Oxygen - Applications, Oxygen - History, Oxygen - Occurrence, Oxygen - Compounds, Oxygen - Isotopes, Oxygen - Precautions

Read more here: » Oxygen: Encyclopedia II - Oxygen - Applications

Oxygen was first discovered by Michał Sędziwój, Polish alchemist and philosopher in late 16th century. Sędziwój assumed the existence of oxygen by warming nitre (saltpeter). He thought of the gas given off as "the elixir of life". Oxygen was again discovered by the Swedish pharmacist Carl Wilhelm Scheele sometime before 1773, but the discovery was not published until after the independent discovery by Joseph Priestley on August 1, 1774, who called the gas dephlogisticated air (see phlogiston theory). Priestley published hi ...

See also:

Oxygen, Oxygen - Characteristics, Oxygen - Applications, Oxygen - History, Oxygen - Occurrence, Oxygen - Compounds, Oxygen - Isotopes, Oxygen - Precautions

Read more here: » Oxygen: Encyclopedia II - Oxygen - History