Year 4 · States of matter
Solids, liquids, gases and the water cycle
Compare and group materials together, according to whether they are solids, liquids or gases
Lesson overview
What you'll learn in this lesson
Compare and group materials together, according to whether they are solids, liquids or gases
Key learning points
- • How to tell them apart
- • Melting and freezing
- • Evaporation and condensation
- • Round and round
This lesson at a glance
- 20 minutes
- 18 parts to scroll through
- 4 quick checks
- No marked quiz yet
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
Watch & discover
Part 1 of 18
Watch first
Solids, liquids, gases 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.
In a nutshell
Compare and group materials together, according to whether they are solids, liquids or gases
What you already know
Part 2 of 18
Before we start
What you already know
You can name materials like wood, water and air.
Key words
Part 3 of 18
Key words
Words you'll need today
- evaporate
- To change from a liquid into a gas.
- condense
- To change from a gas back into a liquid.
- particles
- The tiny bits everything is made of.
Learning cycle
Part 4 of 18
Learning cycle 1 of 2
Part 1 — Three states
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 5 of 18
Learn
How to tell them apart
A solid keeps its own shape and cannot be poured. A liquid takes the shape of its container and can be poured. A gas spreads out to fill all the space it can. Tricky ones: sand pours but each grain is a solid, and jelly holds its shape so it is a solid too.
Explore the idea
Part 6 of 18
Learn
Melting and freezing
Heating a solid enough makes it melt into a liquid; cooling a liquid enough makes it freeze into a solid. Water melts and freezes at 0 °C and boils at 100 °C. The same stuff is still there — only how the particles are arranged has changed.
Quick check
Part 7 of 18
Quick check
Which fills all the space it can?
Reset break
Part 8 of 18
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.
Quick check
Part 9 of 18
Quick check
Water freezes at...
Learning cycle
Part 10 of 18
Learning cycle 2 of 2
Part 2 — The water cycle
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 11 of 18
Learn
Evaporation and condensation
A puddle disappears because the sun warms the water and it evaporates into the air as invisible water vapour. Warmer air, more wind and a bigger surface all make evaporation faster. When water vapour touches something cold it condenses back into droplets — that is why a cold window mists up.
Explore the idea
Part 12 of 18
Learn
Round and round
The sun evaporates water from seas and puddles. The vapour rises, cools and condenses into clouds. Droplets join up until they fall as rain, hail or snow. That water flows into rivers and back to the sea, ready to go round again. No water is ever made or lost.
Quick check
Part 13 of 18
Quick check
A puddle dries up because water...
Quick check
Part 14 of 18
Quick check
Mist on a cold window is...
Common mix-ups
Part 15 of 18
Common mix-ups
Things people often get wrong
- Thinking evaporating water has disappeared instead of becoming a gas.
- Calling sand a liquid because it pours.
- Mixing up condensation and evaporation.
Challenge round
Part 16 of 18
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
Mastery quiz
Part 17 of 18
No quiz for this one
This lesson has no marked quiz attached yet.
Lesson round-up
Part 18 of 18
Lesson round-up
Ready when you are
Quiz score
Not sat
Games
Not played
Points this lesson
0
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 LunaDo 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.
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
WritingWrite 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
WritingExplain 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
DiagramDraw the apparatus or the process in pencil, label it fully, and photograph it.
1 labelled diagram
Reading and notes
ReadingRead the lesson text again and write the key ideas in your own words.
Half a page of notes
Saved as you type.
Part 1 of 18 · Watch & discover