This article is about the chemical use, for computer usage see vaporware

Vapor (US English) or vapour (British English) is the gaseous state of matter.

Although vapor and gas are frequently used interchangeably, vapor often carries the connotation of gaseous matter in a state of equilibrium with identical matter in a liquid or solid state below its boiling point. A liquid or solid does not have to boil to release a vapor. See the entry on vapor pressure for more information on this topic.

The constituent atoms or molecules of a vapor possess vibrational, rotational, and translational motion. More information can be found under the entry of the Kinetic theory of gases.

Examples

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• Perfumes contain chemicals that vaporize at different temperatures. The top note vaporizes first followed by the heart note and the slowest to vaporize is the base note.

• Fog, mist and haar are meteological designations for visible near surface water vapour.

Trivia

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Flammable liquids do not burn when ignited. It is the vapor cloud above the liquid that will burn if the vapor's concentration is between the lower explosive limit and upper explosive limit of the flammable liquid.

See also

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• Evaporation
• Water vapor
• Temperature
• Dilution (equation)

Chemical properties

Dampf | Vapor | Vapore | אד | Damp | 蒸気 | Vapor | Vapor | Höyry | Ånga