Everything for the Matter test: study cards, the traps to dodge, a practice quiz at three levels — Foundation, On-Level, and Challenge — and a lab where you label, graph and argue. Work here, or print it and use a pencil — both count.
Solid: the particles are packed and locked in place. They still jiggle, but they cannot go anywhere.
Count them: fifteen particles in all three pictures. Heat means faster motion, not bigger particles — and since the substance never changed, all three are physical changes.
Four things people get wrong
⚠️People often think…
Dissolving sugar in water is a chemical change.
Melting, boiling, dissolving and cutting are all physical. The sugar is still sugar — boil the water off and it comes back. A chemical change leaves a different substance.
Still the same substance? Physical.
⚠️People often think…
Heating makes the particles themselves get bigger.
The particles stay exactly the same size. They move faster and spread further apart, which is why the whole thing expands.
Faster and further apart — not fatter.
⚠️People often think…
When something burns away, some of the mass is destroyed.
Gases have mass. If the scale drops in an open container, a gas left the container — seal it up and the total never changes. Every atom is still somewhere.
Mass never disappears. Find where the gas went.
⚠️People often think…
A bigger piece of something is denser than a small piece.
Density belongs to the material, not the amount. Half a gold bar is exactly as dense as the whole bar, because the mass and the volume both got cut in half.
Cut it in half and the density does not move.
New substance? Where did the mass go?
1Watch one
An ice cube melts in a glass. Physical change or chemical?
Ask: is it still water?
Yes — same substance, start to finish.
The particles only started moving faster.
Physical change. Freeze it and you get the ice back.
2Do one with me
A log burns down to a small pile of ash. The ash weighs far less than the log did.
Is the ash the same substance as the log?
So the change is
The missing mass left the pile as
💬One sentence, then you move on
How do you tell a physical change from a chemical one?
3Try one
A gold bar is cut in half. Is the smaller piece less dense? Write yes or no.
I want a hint first
Cutting it halved the mass AND the volume. Density is one divided by the other.
💬Last one — then you're done here
When a scale reads less after something burns, where did the mass go?
Where this goes
Where this lives
Cooking an egg you cannot un-cook, rust on a bumper, a soda going flat, and the reason a helium balloon floats.
What this feeds
Next unit is forces, energy and waves — what makes those particles move in the first place.
Name one change you saw today and say whether it was physical or chemical.
One card at a time — tap “Show me” to check yourself, then Next. Start at Foundation; when those feel easy, climb.
Helpful Hints
🪜 From atom to substance — smallest to biggest
Atom → molecule → substance. One kind of atom is an element; two or more kinds bonded in a fixed ratio is a compound; things only stirred together are a mixture.
Letters → words → sentences. Bonded is a word; a mixture is a pile of words.
🤝 The whole topic in one idea
Everything is particles in motion. Heat = faster motion. How fast they move against how hard they hold on decides solid, liquid or gas — and every change either keeps the substance (physical) or makes a new one (chemical), with all the atoms still there.
Ask three things: what are the particles doing, is it a new substance, where did the mass go.
⚠️ Traps the test loves
Melting, boiling, dissolving and cutting are PHYSICAL — the substance is the same afterward.
Heated particles do not get bigger. They move faster and spread out.
A gas has mass. If the scale drops in an open container, a gas left — mass was not destroyed.
Bubbles in boiling water are water vapor, not air.
Density is a property of the STUFF, not the amount. Half a gold bar is just as dense.
🔎 Physical or chemical? The evidence
You see…
It is…
Because…
Ice → water → steam
physical
still H₂O, only the state changed
Bubbles from two mixed liquids
chemical
a new gas formed
Sugar vanishes into tea
physical
dissolved, not changed — evaporate and it’s back
Silver spoon turns black
chemical
tarnish is a new compound
Log becomes ash, smoke, light
chemical
new substances + energy released
New substance? Chemical. Same substance, new form? Physical.
🎯 How the test will ask
A heating graph with a flat line — “what is happening at minute 4?” (a phase change; energy is breaking particles apart, not raising temperature).
Before-and-after masses — “why does the open cup weigh less?” (a gas escaped; in a sealed container it would match).
A formula to count — “how many atoms in 2 H₂O?” (subscripts count atoms in one molecule; the coefficient multiplies the whole molecule).
Three particle pictures — “which is the liquid?” (close together AND out of pattern).
✅ Before the test, can you…
Sort ten changes into physical and chemical and name the clue for each?
Draw the particles of a solid, a liquid and a gas and say what each is doing?
Explain a flat line on a heating graph in one sentence?
Say where the mass went, every time the scale changes?
Tell an element, a compound and a mixture apart from a formula or a description?
Pick your level
Look back at anything you missed — the hint that appeared is exactly what to reread tonight.
How sure did you feel?
Lab
Work like a scientist: label the diagrams, turn the table into a graph, then write a claim with evidence and reasoning. Every lab checks itself on the spot, and hints are free.
Your practice never leaves this device. There is no account and no sign-in. Your work is saved in this browser only, and you can erase it whenever you want.
Your practice record — saved on this device
This is your record of the module on screen — it stays here and goes nowhere. Independent means you got it right on the first tap; supported means you got it after the explain-and-retry, or marked ‘I had it’ on a revealed answer. Both count, and neither is a grade. If your teacher asks, copy the row or show them this screen.
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Explained in own words
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The answer key is for a teacher: it prints only from here, for the unit on screen. Print the study packet prints the study pages and a blank quiz — never the answers.