Year 4 · Autumn 1.2 · Step 1

Earth & Space

Explore solids, liquids and gases

The three states of matter and how to tell them apart by the way they behave.

Arrival Starter I do We do Independent Exit ticket
🌱 Seedling · Working towards 🌿 Sapling · Expected 🌳 Oak · Greater depth

⏱ Whole lesson ≈ 44 min · pick a tier in the bar, or leave on "All"

Arrival 4 min

New topic. Recap Year 3 work on materials and their properties.

Recap: materials around us

🌱 Seedling
Working towards

Name two materials in this classroom.

🌿 Sapling
Expected
  1. Name a hard material and a soft one.
  2. What is an object you use every day made from?
🌳 Oak
Greater depth

Sort three classroom objects by a property you choose. What did you use?

Bridge into todayEverything around us is a solid, a liquid or a gas — the three states of matter. Today we learn to tell them apart.
Starter 5 min

Show the three states; agree the key properties.

Solid, liquid or gas?

A solid keeps its own shape and volume. A liquid keeps its volume but takes the shape of its container. A gas spreads out to fill any space it is in.

🌱 Seedling
Working towards

Which keeps its shape?

a brick · water
🌿 Sapling
Expected

Give an example of a solid, a liquid and a gas.

🌳 Oak
Greater depth

Why does a gas fill the whole room but a puddle does not?

I do · 1 6 min

Teacher models. Watch, then pull out the three key properties.

The three states of matter

▶ Can't see it? Watch "States of Matter — KS2 Science" on YouTube

Swap the clip: change the ID after /embed/ (now 02qBuiqe7qI).

Say thisA solid holds its shape wherever you put it. A liquid flows and takes the shape of its container but keeps the same amount. A gas has no fixed shape and spreads to fill the space.
🧱
Solidfixed shape
💧
Liquidtakes shape
🎈
Gasfills space
We do · 1 6 min

Sort familiar things by state together.

Which state is it?

🧱 brick   💧 water   🫧 the air we breathe   🥛 milk   🎈 helium in a balloon   🪵 wood

Three groups
Solids keep their shape; liquids take the container's shape; gases fill the space.
Ask "does it keep its shape? does it flow? does it spread out?"
I do · 2 4 min

Play the animation. Bust: solid materials can never change shape.

Same jar, three states

solid keeps shape liquidtakes jar shape gasfills the jar

The solid keeps its block shape; the liquid settles to the jar's shape; the gas spreads to fill the jar.

Model the ideaSome solids can change shape — you can bend, squash or stretch them — but they don't flow or fill a space like a liquid or gas do. That's what makes them solid.

Watch for: thinking all solids are hard and unchangeable, and thinking a liquid's amount changes when you pour it.

We do · 2 5 min

Quick true/false to check the properties have stuck.

True or false?

Decide together
"A gas fills any space it is in."   "A liquid keeps its shape when poured."   "All solids are hard and can never bend."
Say which are true and which are wrong, using solid, liquid and gas.
Independent 10 min

On your own. Sort each thing, then write at your tier.

State sorter

🧱 Solid

💧 Liquid

🎈 Gas

Tap a card to sort it…

🌱 Seedling
Working towards

Sort the cards. Then finish: A solid keeps its ____.

🌿 Sapling
Expected

Sort them, then write one property of a solid, a liquid and a gas.

🌳 Oak
Greater depth

Sort them, then explain how you can tell a liquid from a gas.

Exit ticket 4 min

Answer at your tier, then hand it in.

Show what you know

🌱 Seedling
Working towards
  • Name a solid.
  • Name a gas.
🌿 Sapling
Expected
  • How does a liquid behave when you pour it?
  • What does a gas do in a room?
🌳 Oak
Greater depth

Explain the difference between a solid, a liquid and a gas.

TA Focus · The three states
Anchor on behaviour: solid = keeps shape; liquid = takes the container's shape but same amount; gas = fills the space. For the sorter, ask 'does it keep its shape, flow, or spread out?' Gently bust 'all solids are hard' — some bend or squash but still don't flow.
Cold Call · Question bank
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