Gas

Definition

Gas is a state of matter characterized by having neither a fixed shape nor a fixed volume. Gas particles are in constant random motion and are widely spaced compared to liquids and solids.

5 Must Know Facts For Your Next Test

1. Gases exert pressure on the walls of their container due to collisions of gas particles.
2. The behavior of gases can be described by the Ideal Gas Law: $PV = nRT$.
3. Gas particles move in straight lines until they collide with either other particles or the walls of their container.
4. Temperature affects the kinetic energy and therefore the speed of gas particles; higher temperatures increase particle speed.
5. Gases can be compressed more easily than solids and liquids because there is much more space between particles.

Review Questions

• What law describes the relationship between pressure, volume, temperature, and amount of gas?
• How does temperature affect the kinetic energy of gas particles?
• Why are gases more compressible compared to solids and liquids?

Related terms

Ideal Gas Law: A mathematical equation that relates pressure (P), volume (V), amount (n), ideal gas constant (R), and temperature (T) for an ideal gas: $PV = nRT$.

Kinetic Molecular Theory: A theory that explains the behavior of gases, stating that gas particles are in constant random motion and that their collisions with container walls cause pressure.

Boyle's Law: $P1V1 = P2V2$: A principle stating that for a given mass at constant temperature, the volume of a gas is inversely proportional to its pressure.