gas
A gas is a form of matter that has neither a definite shape nor a definite volume. A gas takes up the shape and volume of its container. This is because the particles of a gas are very far apart from one another compared to the particles that make up solids and liquids. Gases are easily compressed because of the large spaces in between gas particles. Gas particles are often invisible, but they can be detected in various ways, such as the light emitted when an electric current is passed through a sample of a gas Figure below .