Particle model of states of matter

The particle model represents matter as small particles. Solids, liquids and gases differ in how their particles are arranged, how far apart they are and how they move.

In the diagrams below, each dot represents a particle.

Solid

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The particles in a solid are closely packed in a regular arrangement. They vibrate about fixed positions rather than moving past one another.

Liquid

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The particles in a liquid are close together but arranged irregularly. They are not fixed in place and can move past one another.

Gas

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The particles in a gas are widely separated and arranged randomly. They move rapidly in all directions.

A static particle diagram shows arrangement and separation, but it cannot show movement on its own. Arrows can be added to indicate particle motion.