Year 4 · States of matter

Evaporation, condensation and the water cycle

Identify the part played by evaporation and condensation in the water cycle and associate the rate of evaporation with temperature

20 minutes4 checks6 exit questionsNational curriculum objective

Lesson overview

What you'll learn in this lesson

Identify the part played by evaporation and condensation in the water cycle and associate the rate of evaporation with temperature

Key learning points

• Evaporation, without boiling
• Condensation, the other way round
• Temperature and speed
• Round and round

This lesson at a glance

20 minutes
19 parts to scroll through
4 quick checks
No marked quiz yet
Gentle pace: short sittings with pauses

Words to know

playedevaporationcondensationassociatetemperature

Scroll down — the lesson carries on below

Part 1 of 19 · Discover5%

Watch & discover

Part 1 of 19

Watch first

Evaporation, condensation and the water cycle

See how the same stuff can be a solid, a liquid or a gas.

Do it for real

The practicals below use what the film shows, with a full method you can follow at home.

The ice cube melting race Make a water cycle in a bag

In a nutshell

Identify the part played by evaporation and condensation in the water cycle and associate the rate of evaporation with temperature

What you already know

Part 2 of 19

Before we start

What you already know

You can sort things into solids, liquids and gases.

Key words

Part 3 of 19

Key words

Words you'll need today

evaporation: A liquid turning into a gas.
condensation: A gas turning back into a liquid.
water vapour: Water as an invisible gas in the air.
precipitation: Rain, hail, sleet or snow falling.

Learning cycle

Part 4 of 19

Learning cycle 1 of 2

Part 1 — Two changes

A short piece of teaching, then a check to make sure it has landed.

Explore the idea

Part 5 of 19

Learn

Evaporation, without boiling

Water does not need to boil to become a gas. A puddle on a warm path disappears because water at the surface escapes into the air as water vapour. Warmer air, wind and a bigger surface all speed it up — which is why washing dries fastest on a warm, breezy day, spread out rather than bundled up.

Explore the idea

Part 6 of 19

Learn

Condensation, the other way round

When water vapour touches something cold, it turns back into liquid drops. That is the mist on a bathroom mirror, the drips on a cold glass of squash, and the fog on the inside of a car window. Nothing has come through the glass — the water was already in the air.

Quick check

Part 7 of 19

Quick check

A puddle drying up is…

Quick check

Part 8 of 19

Quick check

Mist on a cold window is…

Reset break

Part 9 of 19

Pause

That's sitting 1 of 2 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now

Learning cycle

Part 10 of 19

Learning cycle 2 of 2

Part 2 — The cycle

A short piece of teaching, then a check to make sure it has landed.

Explore the idea

Part 11 of 19

Learn

Temperature and speed

The warmer the water, the faster it evaporates. If you leave equal puddles on a sunny windowsill and in a cool cupboard, the sunny one shrinks first. That is a fair test: same amount of water, same size dish, only the temperature changed.

Explore the idea

Part 12 of 19

Learn

Round and round

The sun warms seas, lakes and puddles, so water evaporates. High up the air is colder, so the vapour condenses into tiny droplets that make clouds. Droplets join until they are heavy enough to fall as precipitation. The water runs into rivers, back to the sea, and starts again. No new water is made — it is the same water, used over and over.

Quick check

Part 13 of 19

Quick check

Which dries washing fastest?

Quick check

Part 14 of 19

Quick check

Clouds are made of…

Common mix-ups

Part 15 of 19

Common mix-ups

Things people often get wrong

Thinking water must boil to evaporate.
Thinking condensation on a cold glass leaked out through the glass.
Saying clouds are made of water vapour — they are tiny liquid droplets.

Challenge round

Part 16 of 19

Game · Sort it

Which of these are true?

Drag each card into the right column. Tap a card first if dragging is fiddly.

True

Not true

Challenge round

Part 17 of 19

Game · Fill the gaps

Finish the sentences

Choose the word that belongs in each gap.

That is a fair test: same amount of water, same size dish, only the ____ changed.

Mastery quiz

Part 18 of 19

No quiz for this one

This lesson has no marked quiz attached yet.

Lesson round-up

Part 19 of 19

Lesson round-up

Ready when you are

Quiz score

Not sat

Games

Not played

Points this lesson

Best run

0 in a row

Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?

Ask Luna

Do the work

Your written work for this lesson

This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.

Case study

Why the school greenhouse failed

A science club grew tomato plants in the school greenhouse. In June the plants grew well: leaves were dark green and the fruit set quickly. In July the club went away for two weeks and left the greenhouse door shut. When they came back, the leaves were curled and pale and most of the fruit had dropped.

The club had a data logger inside. It showed the temperature reached 46 °C on several afternoons and the soil moisture fell close to zero. The club knew photosynthesis needs light, water and carbon dioxide, and that enzymes in a plant work best in a narrow range of temperature. Above that range the enzymes stop working properly.

The club repeated the summer with the door propped open and a water bottle drip on each pot. Temperature peaked at 31 °C and the plants survived.

Written for Good Learning Co.

Reading questions

Name the variable the club changed the second time, and one variable they kept the same.
Explain, using the words photosynthesis and enzymes, why the plants were damaged in July.
Write a conclusion for the club's report, saying how far the evidence supports it.

Method and results
Writing
Write the aim, what you changed, what you measured and what you kept the same, then record your results in a table.
1 page + results table
Conclusion
Writing
Explain what your results show and why, using the scientific words from the lesson. Say how you know you can trust them.
6–8 sentences
Labelled diagram
Diagram
Draw the apparatus or the process in pencil, label it fully, and photograph it.
1 labelled diagram
Reading and notes
Reading
Read the lesson text again and write the key ideas in your own words.
Half a page of notes

Write your answer, notes or working here

Saved as you type.

Photos of paper work, diagrams or working outHow many minutes did the written work take?

Part 1 of 19 · Watch & discover

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