Properties of Gases

The Kinetic Molecular Theory is the base of the properties of gases. The following postulates are part of the Kinetic Molecular Theory:

• Gases are composed of molecules whose size is negligible compared to the average distance between them
• Molecules move randomly in straight lines in all directions at various speeds
• The forces of attraction or repulsion between two molecules in a gas are very weak or negligible, except when they collide
• When molecules collide with one another, the collisions are elastic; no kinetic energy is lost
• The average kinetic energy of a molecule is proportional to the absolute temperature