kinetic particle theory

• solids

  Particles of a solid are very closely packed in an orderly manner. They vibrate or rotate only about their fixed positions and have very low kinetic energy. The particles experience strong attractive forces, so a lot of energy is needed to break up the regular arrangement. Hence, a solid has a definite shape and volume.
• liquids

  Particles of a liquid are disorderly arranged and the spacing is larger than in liquid, so the attractive forces are less strong. The particles can slide past one another freely.Thus, a liquid has a definite volume but no definite shape.
• gases

  Particles are very far apart in a disorderly manner and the spacing is so large that the attractive forces between them are very weak. The particles can move quickly and randomly, in any direction. Thus, a gas has no definite shape and volume.