States of Matter

Curriculum Area

Science – Year 4 (Key Stage 2)
National Curriculum Link:

• States of Matter: Compare and group materials together, according to whether they are solids, liquids or gases.
• Observe that materials change state when they are heated or cooled, and measure or research the temperature at which this happens.

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Lesson Objectives

By the end of this 40-minute lesson, students will be able to:

1. Identify and describe the properties of solids, liquids, and gases.
2. Classify different materials based on their state of matter.
3. Explain how materials can change state through heating and cooling.
4. Demonstrate their understanding through a fun, interactive quiz.

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Lesson Structure (40 Minutes)

1. Starter Activity – ‘What Am I?’ (5 Minutes)

• Teacher places objects (ice cube, water bottle, an inflated balloon) on a table.
• Ask students to predict what these objects have in common.
• Introduce the three states of matter: solid, liquid, gas.
• Engage students by asking them to describe the differences they notice between these items.

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2. Direct Teaching (10 Minutes)

Explaining Solids, Liquids & Gases

Solids

• Have a student hold a stone or wooden block.
• Explain that solids have a definite shape and do not flow.

Liquids

• Pour water from one cup to another.
• Explain that liquids take the shape of their container and can flow.

Gases

• Release some air from an inflated balloon.
• Explain that gases spread out to fill the space they are in and can be compressed.

State Changes

• Use an ice cube and a hairdryer to show melting.
• Boil some water (or use pre-recorded video if necessary) to show evaporation.
• Place a clear cup over hot water to observe condensation.

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3. Group Activity – State Sort (10 Minutes)

• Split students into small groups and give them picture cards displaying various objects.
• Groups must sort the objects into solid, liquid, or gas.
• Discuss their answers as a class, with explanations for any misconceptions.

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4. Fun Quiz – 'Matter Mayhem!' (10 Minutes)

• Students answer 6 quickfire questions in teams.
• Example questions:
  1. What state of matter keeps its shape? (Solid)
  2. What state of matter can flow? (Liquid)
  3. What do we call it when a solid turns into a liquid? (Melting)
  4. Name a gas. (Oxygen, helium, etc.)
  5. What happens to water when it freezes? (It becomes a solid - ice.)
  6. What do we call the process when water vapour turns back into liquid? (Condensation)
• Bonus question (tie-breaker): Name a place where you might see condensation in real life.

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Plenary + Reflection (5 Minutes)

• Ask students to summarise one new thing they learned today.
• Pose a thought-provoking question: “What if there were a fourth state of matter?”
• Encourage students to watch for real-world examples of changes in state at home.

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Resources Needed

✔ Ice cubes, hairdryer, cups, water, balloon
✔ Picture sorting cards
✔ Quiz questions on cards or projected on screen
✔ Small whiteboards/paper for answers

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Assessment Opportunities

• Observing student explanations during the sorting activity.
• Monitoring responses in the quiz.
• Listening to student reflections during the plenary.

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Teacher's Wow Moment ✨

• Surprise state change: Drop dry ice into water (if available) to amaze students with bubbling gas!
• Use a mystery box where students feel an object and guess if it is solid, liquid, or gas.

This lesson is designed to be engaging, hands-on, and memorable! Let’s bring science to life! 🚀