- Temperature is a measure of the average kinetic energy of the particles in a substance.
- During a change of state, temperature does not change — energy goes into breaking or forming forces of attraction.
- Gases can be compressed; solids and liquids cannot.
- The four state symbols are (s), (l), (g), (aq).
- Sublimation is solid → gas directly; deposition is gas → solid directly.
- Stronger forces of attraction → higher melting/boiling point.
- The kinetic particle model has limitations — it does not show forces between particles or the real size and internal structure of particles.
This key facts covers Key Facts within States of Matter for GCSE Chemistry. Revise States of Matter in Atomic Structure for GCSE Chemistry with 12 exam-style questions and 10 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 8 of 13 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for States of Matter
Which of the following best describes the arrangement of particles in a solid?
A heating curve shows a flat section (plateau) when a solid is being heated to become a liquid. Explain why the temperature does not rise during this flat section. [3 marks]
Quick recall flashcards
What are the three properties of a solid?
1. Particles are close together in a regular arrangement.
2. Particles only vibrate about fixed positions.
3. Definite shape and definite volume — cannot be compressed.
What are the three properties of a gas?
1. Particles are far apart and in a random arrangement.
2. Particles move quickly in random directions.
3. No fixed shape, no fixed volume — fills the container and can be compressed.