The Particle Theory of Matter is a model which describes the particles
The Particle Theory of Matter is a model which describes the particles, atoms and irons that make up all matter. Key elements of this theory are that: a) all substances—solids, liquids and gases—consist of tiny particles; b) all particles in any substance is in constant movement, even in solids; and c) as they are always in motion, there are always spaces between each particle (D.D, n.d.). Furthermore, in solids, the particles are very attracted and are in a fixed position; in liquids, the particles are still attracted therefore movement is possible though limited; and in gases, there is very little attraction, but collisions and free movement are possible. Moreover, according to the University of Leicester, the particles are either atoms, ions or molecules and the particle movement is based on the amount of energy contained within and their attraction with the surrounding particles (McKeon, 2000).