Learn · Science · Class 3

States of Matter

Solids, liquids and gases, and how one turns into another.

6 parts
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The same water, three waysIcesolidWaterliquidSteamgasHeat spreads them out · cold packs them together
The same water as ice, liquid and steam.
🧩 The partsHow they behavePart 2 of 6
🔍 In detailHeating and coolingPart 3 of 6
✏️ Worked exampleSee it at homePart 4 of 6
✅ SummaryMatter scientist!Part 5 of 6
✏️ Worked exampleWatch one worked throughPart 6 of 6
1📘 DefinitionPart 1 / 6

Three states

Everything around you is a solid, a liquid or a gas.

Ice, water and steam are all the same stuff in three different states!

🎯 Which one keeps its shape?
2🧩 The partsPart 2 / 6

How they behave

  • Solid: keeps its shape, you can hold it
  • Liquid: flows, takes the shape of its container
  • Gas: spreads out everywhere, often invisible
🎯 Milk in a glass is a…
3🔍 In detailPart 3 / 6

Heating and cooling

Heat changes solid → liquid → gas.

Cold changes it back the other way.

ice →(melt)→ water →(boil)→ steam
🎯 What happens to ice when it warms?
4✏️ Worked examplePart 4 / 6

See it at home

Leave an ice cube on a plate. It melts into water.

Boil a kettle. You see steam. Hold a cold spoon above it and water drops appear again. That is condensing.

🎯 Steam turning back into water is called…
5✅ SummaryPart 5 / 6

Matter scientist!

  • Solid keeps shape · liquid flows · gas spreads.
  • Heat moves it towards gas; cold towards solid.
  • Melting, boiling, condensing, freezing.
6✏️ Worked examplePart 6 / 6

Watch one worked through

Here is one done slowly, with the reason for every move. Then one for you.

Let me show you

An ice cube is left on a plate in a warm room. Describe what happens and name each state.

  1. 🧊 SOLID keeps its shape
    At the start the ice is a solid: it keeps its own shape.
    A solid holds its shape wherever you put it. That is the test for a solid.
  2. 🧊 + heat → 💧 melting
    The warm room gives it energy, and it melts into liquid water.
    Heat is what changes a state. Melting always needs energy going in.
  3. 💧 LIQUID takes the plate's shape
    The water spreads out flat because a liquid takes the shape of its container.
    A liquid keeps the same amount but not the same shape. That is the difference from a solid.
  4. 💧 + heat → GAS evaporation
    Left for days it slowly evaporates into a gas and disappears.
    The water has not vanished. It is still there as a gas, just spread through the air where you cannot see it.

Answer: Solid ice melts to liquid water, which evaporates to a gas

Now you try

What is the change from liquid to gas called?

Show the answer

evaporation

Practise States of Matter

Everything on QuizByt for Class 3 Science that goes with this lesson: read it first, then test yourself while it is fresh.

🧠 6 quizzes on States of Matter (3 easy, 2 medium, 1 hard)

Work up from easy to hard: the hard quiz asks the Class 3 exam-style questions on States of Matter.

🖨️ Printable worksheet

States of Matter on paper for Class 3, with room to write the working out. Preview the first page free.

🎮 Games for Class 3 Science

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