Science 7 · Unit 2: Materials and their structure · Cambridge Lower Secondary Science Stage 7

Questions

1. 1. In the water cycle, water evaporates from large areas of water such as lakes and oceans. What does the learner's book call these?

   • water vapour
   • run-off
   • groundwater
   • open water
   Check

2. 2. Water vapour rises and cools high in the air. What happens next?

   • It freezes straight into hailstones.
   • It evaporates again.
   • It condenses into tiny water droplets that form clouds.
   • It turns back into sea water in the air.
   Check

3. 3. What is precipitation?

   • water falling from clouds as rain, snow, sleet or hail
   • water flowing along rivers
   • water taken up by plant roots
   • water vapour rising from the sea
   Check

4. 4. In the water cycle, what is evaporation?

   • water falling from clouds
   • water vapour changing into droplets
   • liquid water changing into water vapour
   • water soaking into the ground
   Check

5. 5. Plants take up water through their roots. Water vapour then leaves through their leaves. What is this part of the cycle called?

   • condensation
   • transpiration
   • run-off
   • precipitation
   Check

6. 6. Rain falls on a hillside and flows over the ground into a stream. What is this called?

   • run-off
   • condensation
   • transpiration
   • evaporation
   Check

7. 7. Some rain soaks into the soil and moves slowly through the rocks back to the sea. What is this water called?

   • water vapour
   • groundwater
   • precipitation
   • clouds
   Check

8. 8. Where does the energy for water to evaporate from the sea come from?

   • the Sun
   • the clouds
   • the wind
   • the Moon
   Check

9. 9. Use particles to explain how water from the ocean reaches the clouds.

   • The wind lifts drops of liquid water straight up into the sky.
   • Water particles become lighter when they meet salt.
   • The water particles lose energy and float up.
   • Some water particles gain energy from the Sun, escape from the surface and rise in the air as a gas.
   Check

10. 10. Why do the water vapour particles condense when they rise high into the sky?

    • The air there is hotter, so the particles speed up.
    • The particles hit the Sun and stick together.
    • There is no air high up, so the particles fall.
    • The air there is colder, so the particles lose energy and come closer together.
    Check

11. 11. Why does it rain?

    • Tiny droplets in a cloud join up into drops too heavy to stay in the air.
    • Clouds melt when they get warm.
    • The Sun pushes the water down.
    • The wind squeezes the clouds.
    Check

12. 12. Put these stages in the order they happen, starting at the sea.

    • precipitation → evaporation → run-off → condensation
    • evaporation → precipitation → condensation → run-off
    • condensation → evaporation → precipitation → run-off
    • evaporation → condensation → precipitation → run-off
    Check

13. 13. Match each stage of the water cycle to what happens.

    • evaporation
    • condensation
    • precipitation
    • transpiration

    • water vapour becomes droplets
    • water falls from clouds
    • water vapour leaves through leaves
    • liquid water becomes a gas
    Check

14. 14. True or false: the water cycle has no start or end; the same water goes round again and again.

    • True
    • False
    Check

15. 15. On a hot, sunny day, which happens faster than on a cold day?

    • condensation into clouds over the sea
    • evaporation from the sea and from puddles
    • the water level rising in the sea
    • freezing of lakes
    Check

16. 16. When does precipitation fall as snow, hail or sleet instead of rain?

    • when the water drops become colder
    • when the Sun is very hot
    • when the clouds are very small
    • when there is no wind at all
    Check