States of Matter

This lesson covers the three states of matter — solid, liquid, and gas — as required by the AQA GCSE Chemistry specification (4.2.4). You need to understand the particle model, state changes, and how to interpret heating and cooling curves. This topic links directly to bonding and structure, as the type of bonding determines the temperatures at which state changes occur.

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The Three States of Matter

All matter exists in one of three states: solid, liquid, or gas. The state of a substance at a given temperature depends on the strength of the forces between its particles.