Particle Model - GCSE Physics Definition

The particle model is a scientific concept used to explain the behaviour and properties of matter by thinking of it as being made up of tiny, invisible particles. In this model, solids, liquids, and gases are described by the way these particles are arranged and how they move. For example, in a solid, particles are tightly packed in a regular pattern and only vibrate in place, while in a liquid, they are close but can move around each other, and in a gas, the particles are far apart and move freely and quickly. This model helps us understand why different materials behave the way they do, like why ice melts into water or why steam arises from boiling water.