State Of Matter - GCSE Chemistry Definition

The state of matter refers to the different forms substances can take (solid, liquid, or gas) depending on how their particles are arranged and how they move. The most common states of matter are solid, liquid, and gas. In a solid, particles are tightly packed together and don't move much, so the solid keeps its shape whereas in a liquid, particles are close together but can move around a bit, allowing the liquid to flow and take the shape of its container. In a gas, the particles are spread out and move freely in all directions, so the gas will fill the entire space of its container. There is also a fourth state, called plasma, which is less common and found in extremely high energy environments like stars. Each state of matter has its own properties, and substances can change from one state to another when heat is added or removed.