What is matter?
Two ordinary objects. One big idea. Find the thing they share.
Pick up a piece of bread. It is real — you can hold it, you can feel it is there. Now hold a balloon. It takes up space, even though it feels almost empty. Both have something in common — and that something is called matter.
The two rules every matter follows
Mass + space — both, not just one.
[A] Look at one lego brick. Now look at a pile of 100 lego bricks stuck together. The pile has more stuff inside it than the single brick — more pieces packed in.
[B] Like a half-empty water bottle versus a fully-filled water bottle — the full one has more water inside, more amount of stuff. We don't say "heavier" — we say "more stuff".
[C] Mass is the amount of matter in something. The more stuff inside, the bigger the mass. We measure mass in kilograms (kg).
Mass is NOT "how heavy" something is. "Heavy" is about gravity pulling — we will learn that later (Year 7 Forces). Mass is about HOW MUCH stuff is inside.
[A] Blow up a balloon. As it gets bigger, it pushes the air around it out of the way.
[B] Like when you sit down on a full sofa, you have to push your friend over to make room — that "make room" feeling is taking up space.
[C] Everything made of matter takes up some space. We call this taking up volume.
All matter has mass AND takes up space. Both, not just one.
[A] You see a tree growing in a forest. The tree just stands there — no one is using it for anything. That tree is matter.
[B] Like flour sitting in your kitchen — flour is just stuff (matter) until someone uses it to bake bread. Once it's used for a purpose, we give it a different name: material.
[C] When someone cuts the tree and uses the wood to build a chair, the wood is now a material. Every material is matter, but not every matter is a material — only when it has a purpose.
Your turn — submit + get feedback
Three questions. Type your answer, click Submit, see if you're right. After 2 tries you can reveal the model answer.
From the next question onwards, you'll see one of these 10 words tagged on top of the question.
Look at these three things: a glass of water, a metal knife, and a rubber eraser. Which of them are matter? Tick all that apply.
Use the two-question test on each item: (1) does it have mass? (2) does it take up space? If both yes → it's matter.
Bonus nudge (Level 1): All three count. Liquids, solids, gases — all can be matter.
Try the two-question test.
All three are matter.
State (liquid/solid/etc.) doesn't decide whether something is matter — having mass + taking up space does.
A balloon looks "empty" because you can't see anything inside, but the air inside still weighs a tiny bit and takes up space. Is the air inside the balloon matter? Explain in one sentence.
Use the two-question test: (1) does air have mass? (2) does air take up space? Use ‘because’ in your sentence.
Bonus nudge (Level 1): The question tells you ‘the air weighs a tiny bit’ AND ‘takes up space’. Both conditions met.
Look — does air pass both rules?
Yes — air is matter, because it has mass and it takes up space.
Matter isn't just things you can see. Air is still matter, even though invisible.
A tree grows in a garden. Someone cuts the tree and uses the wood to make a chair. Look at the three stages: tree → wood → chair.
(a) In the forest, before anyone touched it, the tree is _______ (matter or material?).
(b) The wood used to make the chair is called _______ (matter or material?).
Ask: is it being used for a purpose yet? Yes → material. No → matter. Tree in forest = no use yet. Wood for chair = has a use.
Bonus nudge (Level 1): (a) answer = matter. (b) answer = material.
Read both blanks — does each thing have a use yet?
(a) matter. (b) material.
Same wood, two names — depends on whether it has a purpose. Material = matter with a job to do.
Apply solo — no hints
Two questions. No hint button. Submit your answer — after 2 tries you can reveal the model answer.
Rajiv fills a balloon with helium gas. He puts the balloon inside a tightly sealed box. The box also contains air around the balloon.
The balloon is popped. The helium gas spreads through the box and mixes with the air.
What happens to the mass of the helium? Does it increase, decrease, or stay the same?
The mass of helium stays the same.
Mass is the amount of matter. The helium didn't disappear — it just spread out into the box. Amount stays → mass stays.
Blessy ties two balloons of the same size (both filled with air) to the two ends of a horizontal bar, and balances them.
Blessy pushes a pin into the right-side balloon. The balloon bursts and all the air inside escapes. The other balloon is not touched.
The white balloon (left side) moves downwards — the bar tilts.
What property of air does this model show?
Air has mass.
When the right balloon bursts, the air escapes — that side becomes lighter and the bar tilts. The tilt only happens if the air had mass.
What we learned today
Six big ideas. Your progress. What surprised you?
Key takeaways
What was the one thing today that surprised you most?
We zoom in. Everything around you is made of tiny pieces too small to see. Find out next lesson.