How many rules are there in the particle theory?

The particle theory states that: 1. Everything is made up of tiny particles. 2. These particles are always in motion. 3. There are spaces between the particles. 4. There is an attraction between the particles. (Like a magnetic force) Particles in solids have more attraction than particles in liquids, and particles in gases don't have much attraction at all. Why is the particle theory important to learn about conduction? Move on to the next slide to find out.