Chapter 6 of 7

All 7 chapters
  1. 1Solids, liquids and gases, readunderstood
  2. 2Air is all around us, readunderstood
  3. 3Melting and freezing, readunderstood
  4. 4Evaporation and drying, readunderstood
  5. 5Condensation, readunderstood
  6. 6The water cycle, readunderstood
  7. 7Clean water, readunderstood

S2.4.6 Chapter 6

The water cycle

Where does rain come from, and where does it go?

Your guess

Pick one before you read on. It is fine to be wrong.

Your guess

  • You picked A. Read on. At the end, the chapter comes back to your guess.

  • You picked B. Read on. At the end, the chapter comes back to your guess.

  • You picked C. Read on. At the end, the chapter comes back to your guess.

By the end you can

  • Draw the water cycle with evaporation, condensation, rain and flow
  • Explain how the same water is used again and again

Rain falls on a hill. A river carries it to the sea. The sea does not run out. Where does the water go next?

Draw it first

Draw the water cycle

  1. The sea is at the bottom left, a hill at the right, the Sun at the top left and a cloud at the top right. Two arrows go up from the sea, labelled evaporation. An arrow goes to the cloud, labelled condensation. Rain falls from the cloud, labelled rain. An arrow runs down the hill to the sea, labelled flow.

    1 Draw the sea, a hill, the Sun and a cloud. Add the arrows and the rain.

  2. The sea is at the bottom left, a hill at the right, the Sun at the top left and a cloud at the top right. Two arrows go up from the sea, labelled evaporation. An arrow goes to the cloud, labelled condensation. Rain falls from the cloud, labelled rain. An arrow runs down the hill to the sea, labelled flow.evaporation

    2 Write evaporation by the arrows that go up from the sea.

  3. The sea is at the bottom left, a hill at the right, the Sun at the top left and a cloud at the top right. Two arrows go up from the sea, labelled evaporation. An arrow goes to the cloud, labelled condensation. Rain falls from the cloud, labelled rain. An arrow runs down the hill to the sea, labelled flow.evaporationcondensationrain

    3 Write condensation above the cloud. Write rain by the falling rain.

  4. The sea is at the bottom left, a hill at the right, the Sun at the top left and a cloud at the top right. Two arrows go up from the sea, labelled evaporation. An arrow goes to the cloud, labelled condensation. Rain falls from the cloud, labelled rain. An arrow runs down the hill to the sea, labelled flow.evaporationcondensationrainflow

    4 Write flow by the arrow that runs down to the sea.

The Sun warms the sea, the rivers and the wet ground. Warm water turns into water vapour and rises. This is evaporation. The Sun's heat drives it.

High in the sky the air is cold. The vapour cools and turns into tiny drops. This is condensation.

Very many tiny drops make a cloud. A cloud is not water vapour. You cannot see vapour. A cloud is tiny drops of water, or tiny bits of ice.

Below, small black bits far apart, labelled water vapour, with an arrow labelled rises pointing up. Above, a dotted cloud with a bumpy top and a flat base, labelled cloud, with the words tiny drops inside it. Labels: tiny drops, cloud, water vapour, rises.tiny dropscloudwater vapourrises
Vapour is clear. A cloud is tiny drops you can see.

The drops in a cloud join and grow. They get too heavy to float. They fall as rain. Where it is very cold, they fall as snow.

Three pictures in a row, joined by arrows. First, six tiny circles, labelled tiny, drops. Then three bigger circles, labelled drops, join. Last, one big circle with an arrow pointing down from it, labelled rain falls. Labels: tiny, drops, join, rain falls.tinydropsdropsjoinrain falls
Tiny drops join and grow. Then they fall as rain.

Rain soaks into the ground or runs over it. It flows into streams and rivers. The rivers flow down to the sea. Then the Sun warms the sea again.

The whole round trip is the water cycle. It has no start and no end. You can start at any step.

See it three ways

As a picture

Boxes joined by arrows, labelled in order: sea, vapour, cloud, rain, river, sea. Each arrow points to the next box. The last box is the sea again.seavapourcloudrainriversea

In words

Water goes from the sea into the air as vapour. It makes a cloud. It falls as rain. A river flows back to the sea.

The water on Earth is used again and again. A drop in a puddle may once have been in the sea. It may have been in a cloud, or a river. The same water goes round and round.

Try it

Make a small water cycle

You need: a wide bowl, a small cup that is shorter than the bowl, water, clear plastic, such as a bag cut open, string, a small clean stone, a sunny place.

Be safe: Never drink or taste the water from the bowl or the cup.

  1. Pour water into the bowl, about two fingers deep.
  2. Stand the empty cup in the middle. Keep the water out of it.
  3. Cover the bowl with the plastic. Tie it tight with string.
  4. Put the stone on the plastic, over the cup.
  5. Leave the bowl in the sun for a few hours.
  6. Look at the plastic. Look in the cup.

What you will see: Drops form under the plastic. They run down to the stone and drip into the cup. The Sun warmed the water, and it evaporated. The vapour cooled on the plastic and turned back into drops. This is a small water cycle.

If you cannot try it, this is what happens.
A bowl of water, labelled bowl and water, with a small cup, labelled cup, standing in the middle. Plastic, labelled plastic, covers the bowl. A stone, labelled stone, sits on the plastic so that it dips over the cup. The Sun shines from the top right. Arrows go up from the water. Drops cling under the plastic and one drop falls into the cup.plasticstonewatercupbowl

A wrong idea many people have

When a puddle dries up, its water is gone for ever.

Why it feels right: You cannot see where it went. The ground is dry.

The test that breaks it: Use the bowl in the sun. You pour no water into the cup. Hours later, it holds water. That water came from the bowl. It went up as vapour and came down as drops.

What is true: The water goes into the air as vapour. It comes back later as cloud and rain. It goes round the water cycle.

Key words

evaporation
water turning into water vapour.
condensation
water vapour turning back into drops.
cloud
tiny drops of water, or bits of ice, high in the air.
water cycle
the way water goes from the sea to the sky and back.

Back to your guess

The answer is C: The same water goes round and round, again and again.

The Sun lifts water into the air. It cools, falls as rain and flows back. The same water goes round and round.

Check yourself

Try each one before you look. A wrong answer tells you where to go next.

  1. What does the Sun's heat do in the water cycle?

    Tap your answer.

    1. Yes, that is right. The Sun warms the sea and wet ground. Water turns into vapour and rises.

    2. Not this one. The Sun does not make water. It moves water into the air. Try another.

    3. Not this one. Rain falls because the drops get heavy. The Sun's heat lifts the water. Try another.

    See the answer

    It makes water evaporate and rise.

    The Sun warms the sea and wet ground. Water turns into vapour and rises.

    • If you chose B: The Sun does not make water. It moves water into the air.
    • If you chose C: Rain falls because the drops get heavy. The Sun's heat lifts the water.

  2. What is a cloud made of?

    Tap your answer.

    1. Not this one. You cannot see water vapour. You can see a cloud. A cloud is drops. Go to S2.4.4. Try another.

    2. Yes, that is right. Vapour cools high up and turns into tiny drops. Many drops make a cloud.

    3. Not this one. Smoke is not water. A cloud is drops of water, or ice. Try another.

    See the answer

    Tiny drops of water, or bits of ice

    Vapour cools high up and turns into tiny drops. Many drops make a cloud.

    • If you chose A: You cannot see water vapour. You can see a cloud. A cloud is drops. Go to S2.4.4.
    • If you chose C: Smoke is not water. A cloud is drops of water, or ice.

  3. Look at the picture. Where does the water cycle start?

    The sea is at the bottom left, a hill at the right, the Sun at the top left and a cloud at the top right. Two arrows go up from the sea, labelled evaporation. An arrow goes to the cloud, labelled condensation. Rain falls from the cloud, labelled rain. An arrow runs down the hill to the sea, labelled flow.evaporationcondensationrainflow
    Tap your answer.

    1. Not this one. The water in the sea came from rivers and rain. The cycle goes round. You can start anywhere. Try another.

    2. Not this one. The cloud was made from vapour that rose from the sea. The cycle has no start. Try another.

    3. Not this one. The rain on the hill came from a cloud. The cloud came from vapour that rose from the sea. Try another.

    4. Yes, that is right. Each step leads to the next. The last leads back to the first. It goes round and round.

    See the answer

    It has no start.

    Each step leads to the next. The last leads back to the first. It goes round and round.

    • If you chose A: The water in the sea came from rivers and rain. The cycle goes round. You can start anywhere.
    • If you chose B: The cloud was made from vapour that rose from the sea. The cycle has no start.
    • If you chose C: The rain on the hill came from a cloud. The cloud came from vapour that rose from the sea.

  4. Rain falls on a hill and runs into a river. Where does the water go next?

    Tap your answer.

    1. Not this one. Water is not lost. It flows to the sea and rises again. Try another.

    2. Not this one. The water must first evaporate. The Sun's heat drives that. Go to S2.4.4. Try another.

    3. Yes, that is right. Rivers flow down to the sea. Then the Sun warms the sea, and the water rises again.

    See the answer

    To the sea

    Rivers flow down to the sea. Then the Sun warms the sea, and the water rises again.

    • If you chose A: Water is not lost. It flows to the sea and rises again.
    • If you chose B: The water must first evaporate. The Sun's heat drives that. Go to S2.4.4.

  5. From an earlier chapter

    Snow lies on a hill. The Sun warms it. What happens to the snow?

    Tap your answer.

    1. Not this one. Warmth does not freeze things. Warmth melts ice and snow. Go to S2.4.3. Try another.

    2. Yes, that is right. Heat melts ice and snow. The water then flows down toward the sea.

    3. Not this one. Snow is ice. Heat melts it, and the water runs downhill. Go to S2.4.3. Try another.

    See the answer

    It melts into liquid water.

    Heat melts ice and snow. The water then flows down toward the sea.

    • If you chose A: Warmth does not freeze things. Warmth melts ice and snow. Go to S2.4.3.
    • If you chose C: Snow is ice. Heat melts it, and the water runs downhill. Go to S2.4.3.

  6. Draw the water cycle. Show evaporation, condensation, rain and flow.

    See the answer

    The sea, the Sun, a cloud and a hill. Arrows go up, to the cloud, down as rain and back.

    Water goes up and makes clouds. It falls as rain and flows back to the sea.

  7. Look at the picture. Which letter shows condensation, where vapour cools into tiny drops?

    The sea is at the bottom left, a hill at the right, the Sun at the top left and a cloud at the top right. Two arrows go up from the sea, labelled C. An arrow goes to the cloud, labelled D. Rain falls from the cloud, labelled A. An arrow runs down the hill to the sea, labelled B. Labels: C, D, A, B.CDAB
    Tap your answer.

    1. Not this one. A is where rain falls from the cloud. Condensation is where the cloud forms. Try another.

    2. Not this one. B is the water flowing down the hill to the sea. Condensation is in the sky. Try another.

    3. Not this one. C is where water rises from the sea as vapour. That is evaporation. Go to S2.4.4. Try another.

    4. Yes, that is right. Vapour cools high in the sky and turns into tiny drops. The drops make the cloud, at D.

    See the answer

    Letter D

    Vapour cools high in the sky and turns into tiny drops. The drops make the cloud, at D.

    • If you chose A: A is where rain falls from the cloud. Condensation is where the cloud forms.
    • If you chose B: B is the water flowing down the hill to the sea. Condensation is in the sky.
    • If you chose C: C is where water rises from the sea as vapour. That is evaporation. Go to S2.4.4.

  8. Kofi says today's rain is new water, made in the clouds. Is he right?

    Tap your answer.

    1. Yes, that is right. The same water goes round the water cycle again and again. It is not made new or used up.

    2. Not this one. Clouds do not make water. They hold water that rose from the sea and the land. Try another.

    3. Not this one. Rain is not used up. It flows to the sea, rises again and falls again. Try another.

    See the answer

    No. It is water that has gone round and round.

    The same water goes round the water cycle again and again. It is not made new or used up.

    • If you chose B: Clouds do not make water. They hold water that rose from the sea and the land.
    • If you chose C: Rain is not used up. It flows to the sea, rises again and falls again.

Keep it

Copy this into your exercise book.

The Sun's heat makes water evaporate. The vapour cools into drops. They make clouds. Rain falls and rivers flow to the sea. The same water goes round and round.

Draw: Sea, Sun, cloud and arrows going round. Write the four steps.

Reading with a child? A short page for the adult: what this chapter teaches and three questions to ask.

No internet tomorrow? Save the whole book as one file (712 KB). It opens on any phone.