The particle theory

What is the particle theory of matter?

The particle theory of states

• All matter is made up of particles.
• All particles are attracted to one another.
• All particles are constantly moving.
• Temperature is a measure of the average speed of the particles.

This theory can be used to help explain some of the properties of matter.
 

The Properties of Solids, Liquids and Gases and the Particle Theory

	Solid	Liquid	Gas
Properties	fixed shape fixed volume cannot be compressed no diffusion*	variable shape fixed volume cannot be compressed slow diffusion*	variable shape variable volume can be compressed rapid diffusion*
Beaker
Conical flask
Particle theory	The particles are close together and are vibrating in fixed positions.	The particles are close together and are moving slowly over one another.	The particles are far apart and are moving quickly past one another.

 * Diffusion is the random movement of particles from an area of high concentration to an area of low concentration.