
Leo notices that his soccer ball feels much harder in the day, when it is hot, compared to at night when it is cooler. Use particle theory to explain why.
Important Questions on Elements, Compounds and Mixtures
When a coloured sweet is added to water, the dye dissolves in the water and diffuses away from the sweet. Use this to plan an investigation to test the idea that temperature affects the rate of diffusion. Write your plan:
What variable will you change? How will you change this and what range will you choose?
What variable will you measure?
What variables need to be kept the same?

When a coloured sweet is added to water, the dye dissolves in the water and diffuses away from the sweet. Use this to plan an investigation to test the idea that temperature affects the rate of diffusion. Write your plan:
Make a prediction: what do you think your results will show?

When a coloured sweet is added to water, the dye dissolves in the water and diffuses away from the sweet. Use this to test the idea that temperature affects the rate of diffusion.
Use particle theory to explain your results.
Use what you know about diffusion to explain why:
- You can smell what is cooking in the kitchen from another room.

Use what you know about diffusion to explain why:
- The colour from a teabag spreads throughout a cup of water.

Use what you know about diffusion to explain why:
- The smell of a scented candle is much stronger when it is lit.

Use what you know about diffusion to explain why:
- Diffusion happens more quickly in gases than in liquids.

