Oxygen Facts
Atomic Number 8
Symbol O
Atomic Weight 15.9994
Discovery Joseph Priestley; Scheele 1774.
Electron Configuration [He]2s22p4
Word Origin Greek: oxys: sharp or acid and Greek: genes: born, former... 'acid former'.
Isotopes Nine isotopes of oxygen are known. Natural oxygen is a mixture of three isotopes.
Properties Oxygen gas is colorless, odorless, and tasteless. The liquid and solid forms are a pale blue color and are strongly paramagnetic. Oxygen supports combustion, combines with most elements, and is a component of hundreds of thousands of organic compounds. Ozone (O3), a highly active compound with a name derived from the Greek word for 'I smell', is formed by the action of an electrical discharge or ultraviolet light on oxygen.
Uses Oxygen was the atomic weight standard of comparison for the other elements until 1961 when the International Union of Pure and Applied Chemistry adopted carbon 12 as the new basis. It is the third most abundant element found in the sun and the earth, and it plays a part in the carbon-nitrogen cycle. Excited oxygen yields the bright red and yellow-green colors of the Aurora. Oxygen enrichment of steel blast furnaces accounts for the greatest use of the gas. Large quantities are used in making synthesis gas for ammonia, methanol, and ethylene oxide. It is also used as a bleach, for oxidizing oils, for oxy-acetylene welding, and for determining carbon content of steel and organic compounds. Plants and animals require oxygen for respiration. Hospitals frequently prescribe oxygen for patients. Approximately two thirds of the human body and nine tenths of the mass of water is oxygen.
Oxygen can exist in a number of physical forms. Most commonly it is found as a diatomic O-O gas and is called molecular oxygen (O2) or dioxygen. The gas exists as a triplet state but the singlet oxygen can also be formed and is more reactive. This gas can be liquefied at low temperatures to produce a blue liquid oxygen (LOX) and cooled further produces a blue solid. After electrical discharge or photolysis Oxygen may also form the triatomic ozone (O3) and under very extreme conditions atomic oxygen (O•) is produced.
2006-11-10 23:48:15
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answer #1
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answered by blapath 6
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