The three states of matter — AQA GCSE Chemistry
Test yourself on The three states of matter with AQA GCSE practice questions.
7 days Premium · Then free forever · No card, no charge
The three states of matter explained
Matter can exist in three physical states: solid, liquid and gas.
Read the full explanation
The state depends on the arrangement, spacing and movement of the particles, and on the strength of the forces between them. In a solid, particles are close together in a regular arrangement and vibrate about fixed positions, so a solid has a fixed shape and volume. In a liquid, particles are close together but randomly arranged and can slide past one another, so a liquid has a fixed volume but takes the shape of its container. In a gas, particles are far apart, randomly arranged and move quickly in all directions, so a gas fills its container and is easily compressed. For example, ice, water and steam are the solid, liquid and gas states of the same substance. Changes of state are physical changes and do not alter the chemical identity of the substance.
Your focus
- Name and describe the three states of matter using the particle model.
- Compare the arrangement, spacing and movement of particles in solids, liquids and gases.
- Explain everyday observations using the particle model of the three states.
The three states of matter exam tips
Marking Points
- Names the three states of matter as solid, liquid and gas.
- Describes the arrangement and spacing of particles in each state.
- Describes the movement of particles in each state.
- Links the particle model to properties such as shape, volume or compressibility.
- Recognises that changes of state are physical changes and are reversible.
Examiner Tips
- 💡Use a simple particle diagram for each state and label spacing and arrangement.
- 💡Compare the three states in a table to make differences clear.
- 💡When explaining a property, always refer to both particle arrangement and particle movement.
Common Mistakes
- Stating that particles in a gas do not move; correct this by saying gas particles move quickly and randomly.
- Saying that particles in a liquid are far apart; correct this by stating that liquid particles are close together but can slide past one another.
- Describing changes of state as chemical changes; correct this by stating that they are physical changes.