The Water Cycle in Detail · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Tracing the Water Cycle

Science · Ecosystems & Habitats · ages 11-12
Name ______________________   Date ____________

  1. What provides the heat energy that turns water into vapour during evaporation?

    • The sun
    • The wind
    • The moon

  2. Which stage of the water cycle happens when liquid water turns into vapour and rises into the air?

    • Evaporation
    • Precipitation
    • Runoff

  3. Plants only take in water through their roots. They never release any water back into the air.

    Circle one:   True   False

  4. A grassy field is paved over to make a car park. What happens to the rain that falls on it now?

    • More of it soaks into the ground slowly
    • More of it runs off quickly across the surface
    • It stops evaporating completely

  5. This shows three water cycle stages in order, but the middle one is missing. Which stage fills the gap between evaporation and precipitation?

    Evaporate?Precipitate
    • Condensation
    • Transpiration
    • Runoff

  6. Which process explains why a forest releases extra water vapour into the air on a hot day?

    • Transpiration: water vapour escaping through pores in the leaves
    • Precipitation: rain falling from the leaves
    • Runoff: water flowing off the leaves into streams

  7. A hillside forest is cut down and replaced with paved roads. Streams below start flooding more often after storms. Why?

    • Less transpiration and less soil mean rain runs off fast into the streams
    • Paving makes it rain more often on the hillside
    • Cutting the trees stops evaporation completely, so all the rain becomes flood water

  8. Ben says the water cycle completely stops every night because the sun goes down. What is wrong with his idea?

    • Nothing is wrong, he is correct
    • Stored heat keeps some evaporation going and clouds still release rain at night, so the cycle keeps moving
    • Evaporation actually speeds up once it gets dark
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Tracing the Water Cycle W1-mt_V2lNzEex_a-s1

  1. The sun · Solar energy heats water and turns it into vapour; that heat is what drives evaporation.
  2. Evaporation · Evaporation is water changing from liquid to vapour and rising into the air.
  3. False · Plants take in water through their roots, but they also release water vapour from their leaves. That is called transpiration.
  4. More of it runs off quickly across the surface · Pavement stops water soaking in, so more rain becomes fast surface runoff instead.
  5. Condensation · Water vapour cools and clumps into clouds during condensation, the step between evaporation and precipitation.
  6. Transpiration: water vapour escaping through pores in the leaves · Trees release water vapour through tiny leaf pores called stomata. This transpiration adds moisture to the air.
  7. Less transpiration and less soil mean rain runs off fast into the streams · Trees and soil normally soak up and slow down rainwater. Without them, water runs straight off the bare, paved hillside into streams.
  8. Stored heat keeps some evaporation going and clouds still release rain at night, so the cycle keeps moving · The sun drives the cycle, but heat stored in the oceans and air during the day keeps water moving even after sunset.
Worksheet · LightMySky