Changes

==Etymology==

==Etymology==

New Latin, alteration of [[Latin]] [[chaos]] [[space]]

New Latin, alteration of [[Latin]] [[chaos]] [[space]]

*Date: [http://www.wikipedia.org/wiki/18th_Century 1779]

*Date: [https://www.wikipedia.org/wiki/18th_Century 1779]

==Definitions==

==Definitions==

*1 : a [[fluid]] (as air) that has neither [[independent]] shape nor [[volume]] but tends to expand indefinitely

*1 : a [[fluid]] (as air) that has neither [[independent]] shape nor [[volume]] but tends to expand indefinitely

*6 slang : something that gives [[pleasure]] : delight <the party was a gas>

*6 slang : something that gives [[pleasure]] : delight <the party was a gas>

==Description==

==Description==

'''Gas''' is one of three [[classical]] [[states]] of [[matter]]. Near [http://en.wikipedia.org/wiki/Absolute_zero absolute zero], a substance exists as a [[solid]]. As [[heat]] is added to this substance it melts into a [[liquid]] at its [http://en.wikipedia.org/wiki/Melting_point melting point] (see [[phase change]]), boils into a gas at its [http://en.wikipedia.org/wiki/Boiling_point boiling point], and if heated high enough would enter a [[plasma]] [[state]] in which the [[electrons]] are so energized that they leave their [[parent]] [[atoms]] from within the gas. A [[pure]] gas may be made up of [[individual]] [[atoms]] (e.g. a [http://en.wikipedia.org/wiki/Noble_gas noble gas] or atomic gas like neon), elemental [[molecules]] made from one type of [[atom]] (e.g. oxygen), or [http://en.wikipedia.org/wiki/Chemical_compound compound] molecules made from a variety of [[atoms]] (e.g. carbon dioxide). A gas [http://en.wikipedia.org/wiki/Mixture  mixture] would contain a variety of [[pure]] gases much like the air. What distinguishes a gas from [[liquids]] and [[solids]] is the vast separation of the individual gas [[particles]]. This separation usually makes a colorless gas [[invisible]] to the [[human]] [[observer]]. The [[interaction]] of gas particles in the [[presence]] of [[electric]] and [[gravitational]] fields  are considered negligible.

'''Gas''' is one of three [[classical]] [[states]] of [[matter]]. Near [https://en.wikipedia.org/wiki/Absolute_zero absolute zero], a substance exists as a [[solid]]. As [[heat]] is added to this substance it melts into a [[liquid]] at its [https://en.wikipedia.org/wiki/Melting_point melting point] (see [[phase change]]), boils into a gas at its [https://en.wikipedia.org/wiki/Boiling_point boiling point], and if heated high enough would enter a [[plasma]] [[state]] in which the [[electrons]] are so energized that they leave their [[parent]] [[atoms]] from within the gas. A [[pure]] gas may be made up of [[individual]] [[atoms]] (e.g. a [https://en.wikipedia.org/wiki/Noble_gas noble gas] or atomic gas like neon), elemental [[molecules]] made from one type of [[atom]] (e.g. oxygen), or [https://en.wikipedia.org/wiki/Chemical_compound compound] molecules made from a variety of [[atoms]] (e.g. carbon dioxide). A gas [https://en.wikipedia.org/wiki/Mixture  mixture] would contain a variety of [[pure]] gases much like the air. What distinguishes a gas from [[liquids]] and [[solids]] is the vast separation of the individual gas [[particles]]. This separation usually makes a colorless gas [[invisible]] to the [[human]] [[observer]]. The [[interaction]] of gas particles in the [[presence]] of [[electric]] and [[gravitational]] fields  are considered negligible.

The gaseous [[state]] of [[matter]] is found between the [[liquid]] and [[plasma]] states, the latter of which provides the upper [http://en.wikipedia.org/wiki/Temperature temperature] boundary for gases. Bounding the lower end of the [http://en.wikipedia.org/wiki/Temperature temperature] [[scale]] lie degenerative [[quantum]] gases which are gaining increased [[attention]] these days. High-[[density]] atomic gases super cooled to incredibly low temperatures are [[classified]] by their [[statistical]] [[behavior]] as either a [http://en.wikipedia.org/wiki/Bose_gas Bose gas] or a [http://en.wikipedia.org/wiki/Fermi_gas Fermi gas].[http://en.wikipedia.org/wiki/Gas]

The gaseous [[state]] of [[matter]] is found between the [[liquid]] and [[plasma]] states, the latter of which provides the upper [https://en.wikipedia.org/wiki/Temperature temperature] boundary for gases. Bounding the lower end of the [https://en.wikipedia.org/wiki/Temperature temperature] [[scale]] lie degenerative [[quantum]] gases which are gaining increased [[attention]] these days. High-[[density]] atomic gases super cooled to incredibly low temperatures are [[classified]] by their [[statistical]] [[behavior]] as either a [https://en.wikipedia.org/wiki/Bose_gas Bose gas] or a [https://en.wikipedia.org/wiki/Fermi_gas Fermi gas].[https://en.wikipedia.org/wiki/Gas]

[[Category: Physics]]

[[Category: Physics]]