General purpose of this lecture is to present on Particle model of Solids, Liquids and Gases. Particle Model of Solids, Liquids and Gases. All matter is made of up particles, these particles behave in different ways whether they are solid, liquid or gas. Particles in solids are held together very closely. Particles in liquids are quite close to each other, however they can move past each other very easily. Particles in gases move around very quickly with a lot of space between them, this means you can compress them very easily.