gas: Quick Facts

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Facts

Also Known As	gaseous state

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A diagram showing a bottle with a balloon over its opening, first at room temperature and then heated. As the bottle is heated, the air inside expands, inflating the balloon to demonstrate the principle of thermal expansion.

Diagram showing the phase changes of matter with three circles labeled solid, liquid, and gas. Arrows indicate transitions: melting and freezing between solid and liquid, evaporation and condensation between liquid and gas, and sublimation and deposition between solid and gas.

Diagram showing four physical states of matter: solid with tightly packed molecules, liquid with loosely packed molecules, gas with widely spaced molecules, and plasma with free electrons and nuclei, each labeled with descriptions and an arrow indicating increasing energy.

An illustration shows an ice cube labeled solid, a puddle labeled liquid, and rising steam labeled gas, representing the three states of matter: ice, water, and water vapor, with the sun in the background.

Figure 2: The atomic arrangements in (A) a crystalline solid, (B) an amorphous solid, and (C) a gas.

A diagram of a cylindrical vessel containing gas, with a movable piston held down by a weight. Countless small dots beneath the piston represent gas particles in rapid, random motion, illustrating Bernoulli's model of gas pressure.

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Topics

effusion thermomolecular pressure difference continuum gas free-molecule gas Loschmidt’s number optical depth static theory of gases syngas ideal gas kinetic theory of gases liquid solid radiation chemical bonding chemical element subatomic particle atom electricity chemical compound time

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Key People

Joseph Priestley

Joseph Priestley

English clergyman and scientist

James Clerk Maxwell

James Clerk Maxwell

Scottish mathematician and physicist

Henry Cavendish

Henry Cavendish

British physicist

Joseph-Louis Gay-Lussac, engraving by Ambroise Tardieu.

Joseph-Louis Gay-Lussac

French scientist

Sir Humphry Davy

Sir Humphry Davy

English chemist

John Dalton

John Dalton

British scientist

J.J. Thomson

J.J. Thomson

British physicist

Langmuir, Irving

Irving Langmuir

American chemist

Robert Boyle

Robert Boyle

Anglo-Irish philosopher and writer

Amedeo Avogadro

Amedeo Avogadro

Italian physicist

Helmont, Jan Baptista van

Jan Baptista van Helmont

Belgian scientist

Johannes Diederik van der Waals

Dutch physicist

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Sir John Sealy Townsend

Irish physicist

Henri-Victor Regnault

Henri-Victor Regnault

French chemist and physicist

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Eugen Goldstein

German physicist

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