This definitions covers Key Definitions within States of Matter for GCSE Physics. Revise States of Matter in Particle Model for GCSE Physics with 13 exam-style questions and 30 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 8 of 13 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
📖 Key Definitions
Melting point: The temperature at which a solid changes to a liquid. Temperature stays constant during melting as energy breaks intermolecular bonds.
Boiling point: The temperature at which a liquid changes to a gas throughout the bulk liquid. Temperature stays constant during boiling.
Internal energy: The total kinetic and potential energy of all the particles in a substance.
Latent heat: The energy needed to change state without changing temperature. It goes into breaking or forming bonds (changing potential energy).
Evaporation: A surface process where higher-energy particles escape from a liquid below its boiling point. Distinct from boiling (which happens throughout the liquid).
Sublimation: A direct change from solid to gas without passing through the liquid state (e.g. dry ice / frozen CO₂).
Practice questions for States of Matter
In which state of matter are particles arranged in a regular pattern and only vibrate about fixed positions?
Explain what happens to the particles in a solid when it is heated until it melts. Include what happens to the temperature during melting.