1. Candle wax changing from solid to liquid is an example of:

2. What is the primary purpose of a freezer?

3. The main reason water disappears from a steel plate (Activity 8.2) is:

4. The main reason water droplets form on a cold tumbler (Activity 8.3) is:

5. What is the state of water vapour at room temperature?

6. Water vapour in the air is:

7. What happens to the water level in the modified Activity 8.4?

8. What does the constant water level in the tumbler prove?

9. What does the increase in mass on the balance prove?

10. What is the key factor for condensation to occur?