Success Homeschool

Year 8 Science · The particle model of matter

Name: ______________________

Date: ____________

1. Which best describes particles in a solid?
- ☐ (a) Far apart and moving fast
- ☐ (b) Close together, vibrating in fixed positions
- ☐ (c) Close together and sliding past each other
- ☐ (d) Not moving at all
2. Why can gases be compressed easily?
- ☐ (a) Their particles are very small
- ☐ (b) Their particles are hot
- ☐ (c) There are large spaces between their particles
- ☐ (d) Their particles do not move
3. What happens to particles when a substance is heated?
- ☐ (a) They move faster
- ☐ (b) They get bigger
- ☐ (c) They stop moving
- ☐ (d) They melt
4. Why do railway lines have small gaps between sections?
- ☐ (a) To save steel
- ☐ (b) To make a clicking noise
- ☐ (c) To let rain drain away
- ☐ (d) To allow for expansion in hot weather
5. You can smell a barbecue from next door because of…
- ☐ (a) Condensation
- ☐ (b) Diffusion
- ☐ (c) Freezing
- ☐ (d) Compression
6. What is the spreading of particles from high to low concentration called?
7. Which state of matter has particles that are close together but can slide past each other?
8. What type of energy do particles gain when they move faster? (one word) ______ energy

Answer sheet

1. Close together, vibrating in fixed positions — Solid particles are tightly packed and vibrate on the spot.
2. There are large spaces between their particles — Large gaps between gas particles allow them to be pushed closer together.
3. They move faster — Heating gives particles more kinetic energy; the particles themselves do not grow.
4. To allow for expansion in hot weather — Steel expands when hot; gaps stop the rails buckling.
5. Diffusion — Smell particles diffuse through the air from the barbecue to your nose.
6. diffusion — This is diffusion.
7. liquid — Liquid particles touch but can move past one another.
8. kinetic — Energy of movement is kinetic energy.