Science · Year 5

Active learning ideas

Reversible Changes

Active learning works well for reversible changes because students need to see and feel physical processes to grasp the concept fully. Watching ice melt and refreeze or dissolving sugar then evaporating it helps students move from abstract ideas to concrete evidence they can observe and discuss.

• National Curriculum Attainment Targets
• NC-KS2-Science-Y5-PCM-6

• 20–45 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Inquiry Circle
• 30 min · Pairs

Pairs Test: Melting and Freezing

Pairs heat ice cubes in warm water, record temperature changes, then place in freezer to refreeze. They measure mass before and after to check conservation. Discuss if the ice returns to original form.

Explain how we know if a change is reversible.

Facilitation Tip

During the Pairs Test: Melting and Freezing, circulate and ask each pair to explain why the ice’s change is reversible using their observations of state and temperature.

What to look for

Present students with a list of changes (e.g., burning paper, freezing water, mixing flour and water, boiling an egg). Ask them to circle the reversible changes and put a line through the irreversible ones. Follow up by asking them to explain their reasoning for two of their choices.

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Activity 02

• Inquiry Circle
• 45 min · Small Groups

Small Groups: Dissolving Challenge

Groups dissolve salt in warm water, stir, then evaporate using heat lamps or sun. Filter if needed and weigh recovered salt. Compare with undissolved sample to confirm reversibility.

Compare the processes of melting ice and dissolving sugar, identifying similarities.

Facilitation Tip

In the Small Groups: Dissolving Challenge, provide measuring spoons for both before and after dissolving to directly address the misconception that dissolving destroys the solute.

What to look for

Pose the question: 'Imagine you dissolve sugar in a glass of water. How do you know the sugar is still there, even though you can't see it? How could you get the sugar back?' Facilitate a class discussion where students share their ideas and connect them to the concepts of dissolving and evaporation.

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Activity 03

• Inquiry Circle
• 35 min · Whole Class

Whole Class: Prediction Relay

Display materials like paper, clay, ink. Class predicts reversibility in teams, tests one by one: fold/unfold paper, mould/remould clay. Vote and justify after each trial.

Predict the reversibility of various changes and justify your predictions.

Facilitation Tip

For the Whole Class: Prediction Relay, have students justify their predictions using evidence from prior activities to reinforce connections between ideas.

What to look for

Give each student a small card. Ask them to write down one example of a reversible change they observed today and one example of an irreversible change. For the reversible change, they should briefly explain how it could be undone.

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Activity 04

• Inquiry Circle
• 20 min · Individual

Individual: Home Link Observation

Students select household item, test reversible change like butter melting, record steps and photos. Share findings next lesson to build class examples database.

Explain how we know if a change is reversible.

What to look for

Present students with a list of changes (e.g., burning paper, freezing water, mixing flour and water, boiling an egg). Ask them to circle the reversible changes and put a line through the irreversible ones. Follow up by asking them to explain their reasoning for two of their choices.

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

A few notes on teaching this unit

Teaching reversible changes effectively starts with hands-on experiments that let students test ideas themselves. Avoid lecturing about state changes; instead, guide them to observe and explain. Research shows students learn best when they connect their prior knowledge to new evidence through discussion and reflection.

Successful learning looks like students confidently explaining why some changes can be reversed while others cannot. They should use evidence from their experiments to support their answers and correct peers’ misconceptions during group discussions.

---

Watch Out for These Misconceptions

• During Small Groups: Dissolving Challenge, watch for students who believe the sugar disappears forever.

  Have students weigh the sugar before dissolving and after evaporation to show the mass remains the same, using measuring spoons and a simple balance.

• During Whole Class: Prediction Relay, watch for students who assume all heating causes reversible changes.

  Use the relay stations to test multiple materials like chocolate, bread, and ice, and have students classify outcomes based on whether the substance remains unchanged.

• During Pairs Test: Melting and Freezing, watch for students who think mixing sand and water is irreversible like baking a cake.

  Provide filter paper and funnels so students can separate the sand and water, demonstrating that the substances can be recovered unchanged.

---

Methods used in this brief

• Inquiry Circle