Adjacent Words

Oxygen definitions

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Webster's 1828 Dictionary

OX'YGEN, n. [Gr. acid, and to generate.]
In chimistry, oxygen or oxygen gas is an element or substance so named from its property of generating acids; it is the respirable part of air, vital air, or the basis of it; it is called the acidifying principle, and the principle or support of combustion. Modern experiments, however, prove that it is not necessary in all cases to combustion or to acidity. Oxygen is a permanently elastic fluid, invisible, inodorous, and a little heavier than atmospheric air. In union with azote or nitrogen, it forms atmospheric air, of which it constitutes about a fifth part. Water contains about 85% of it, and it exists in most vegetable and animal products, acids, salts and oxyds. It forms 50% of silex, 47 of alumin, 28 of lime, 40 of magnesia, 17 of potash, and 25 of soda.

WordNet (r) 3.0 (2005)

n
1: a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust [syn: oxygen, O, atomic number 8]

Merriam Webster's

noun Usage: often attributive Etymology: French oxygène, from Greek oxys, adjective, acidic, literally, sharp + French -gène -gen; akin to Latin acer sharp — more at edge Date: 1788 1. a reactive element that is found in water, in most rocks and minerals, in numerous organic compounds, and as a colorless tasteless odorless diatomic gas constituting 21 percent of the atmosphere, that is capable of combining with all elements except the inert gases, that is active in physiological processes, and that is involved especially in combustion — see element table 2. something that sustains or fuels <disagreement is the true oxygen of these magazines — Joseph Epstein> • oxygenless adjective

Britannica Concise

Gaseous chemical element, chemical symbol O, atomic number 8. It constitutes 21% (by volume) of air and over 46% (by weight) of the earth's crust, where it is the most plentiful element. It is a colorless, odorless, tasteless gas, occurring as the diatomic molecule O2. In respiration, it is taken up by animals and some bacteria (and by plants in the dark), which give off carbon dioxide (CO2). In photosynthesis, green plants assimilate carbon dioxide in the presence of sunlight and give off oxygen. The small amount of oxygen that dissolves in water is essential for the respiration of fish and other aquatic life. Oxygen takes part in combustion and in corrosion but does not itself burn. It has valence 2 in compounds; the most important is water. It forms oxides and is part of many other molecules and functional groups, incl. nitrate, sulfate, phosphate, and carbonate; alcohols, aldehydes, carboxylic acids, and ketones; and peroxides. Obtained for industrial use by distillation of liquefied air, oxygen is used in steelmaking and other metallurgical processes and in the chemical industry. Medical uses include respiratory therapy, incubators, and inhaled anesthetics. Oxygen is part of all gas mixtures for spacecraft, scuba divers, workers in closed environments, or hyperbaric chambers. It is also the oxidizer in rocket engines and in water and waste treatment processes.

Dictionary of the Elements

oxygen
Symbol: O
Atomic number: 8
Atomic weight: 15.9994
A colourless, odourless gaseous element belonging to group 16 of the periodic table. It is the most abundant element present in the earth's crust. It also makes up 20.8% of the Earth's atmosphere. For industrial purposes, it is separated from liquid air by fractional distillation. It is used in high temperature welding, and in breathing. It commonly comes in the form of Oxygen, but is found as Ozone in the upper atmosphere. It was discovered by Priestley in 1774.

Oxford Reference Dictionary

n. Chem. a colourless tasteless odourless gaseous element, occurring naturally in air, water, and most minerals and organic substances, and essential to plant and animal life. Usage: Symb.: O. Phrases and idioms: oxygen mask a mask placed over the nose and mouth to supply oxygen for breathing. oxygen tent a tentlike enclosure supplying a patient with air rich in oxygen. Derivatives: oxygenous adj. Etymology: F oxygène acidifying principle (as OXY- 2): it was at first held to be the essential principle in the formation of acids

Webster's 1913 Dictionary

Oxygen Ox"y*gen, n. [F. oxyg[`e]ne, from Gr. ???? sharp, acid + root of ???? to be born. So called because originally supposed to be an essential part of every acid.] 1. (Chem.) A colorless, tasteless, odorless, gaseous element occurring in the free state in the atmosphere, of which it forms about 23 per cent by weight and about 21 per cent by volume, being slightly heavier than nitrogen. Symbol O. Atomic weight 15.96. Note: It occurs combined in immense quantities, forming eight ninths by weight of water, and probably one half by weight of the entire solid crust of the globe, being an ingredient of silica, the silicates, sulphates, carbonates, nitrates, etc. Oxygen combines with all elements (except fluorine), forming oxides, bases, oxyacid anhydrides, etc., the process in general being called oxidation, of which combustion is only an intense modification. At ordinary temperatures with most substances it is moderately active, but at higher temperatures it is one of the most violent and powerful chemical agents known. It is indispensable in respiration, and in general is the most universally active and efficient element. It may be prepared in the pure state by heating potassium chlorate. This element (called dephlogisticated air by Priestley) was named oxygen by Lavoisier because he supposed it to be a constituent of all acids. This is not so in the case of a very few acids (as hydrochloric, hydrobromic, hydric sulphide, etc.), but these do contain elements analogous to oxygen in property and action. Moreover, the fact that most elements approach the nearer to acid qualities in proportion as they are combined with more oxygen, shows the great accuracy and breadth of Lavoisier's conception of its nature. 2. Chlorine used in bleaching. [Manufacturing name]

Collin's Cobuild Dictionary

Oxygen is a colourless gas that exists in large quantities in the air. All plants and animals need oxygen in order to live. The human brain needs to be without oxygen for only four minutes before permanent damage occurs.

Moby Thesaurus

acetylene, ammonia, argon, asphyxiating gas, butane, carbon dioxide, carbon monoxide, chlorine, coal gas, ethane, ether, ethylene, fluorine, formaldehyde, helium, hydrogen, illuminating gas, krypton, lewisite, marsh gas, methane, mustard gas, natural gas, neon, nitrogen, ozone, poison gas, propane, radon, sewer gas, xenon