Reversible and Irreversible Changes KS2
Teaching reversible and irreversible changes KS2 helps children understand how materials can change and whether those changes can be undone. This important Year 5 science topic encourages children to investigate materials, observe changes and explain what happens when substances are heated, cooled, mixed or altered.
Whether you're introducing the topic for the first time or looking for engaging lesson ideas, this guide explains reversible and irreversible changes in a child-friendly way and provides links to ready-made teaching resources.
Teaching reversible and irreversible changes?
Save planning time with this ready-to-teach lesson, including lesson plan, slideshow and differentiated, hands-on activities.
What Are Reversible and Irreversible Changes?
A reversible change is a change that can be undone. The material remains the same substance, even though it may look different.
Examples of reversible changes include:
- Ice melting into water
- Water freezing into ice
- Chocolate melting and hardening again
- Sugar dissolving in water
- Water evaporating and condensing
An irreversible change is a change that cannot be undone. Often, a new material is created during the process.
Examples of irreversible changes include:
- Burning wood or paper
- Cooking an egg
- Baking a cake
- Rusting iron
- Mixing substances that cause a chemical reaction
Reversible and Irreversible Changes Year 5
The National Curriculum teaches reversible and irreversible changes Year 5 as part of the Properties and Changes of Materials unit.
Children are expected to:
- Compare and group materials according to their properties
- Understand that some changes are reversible while others are irreversible
- Recognise that some irreversible changes create new materials
- Use evidence from investigations to support conclusions
- Develop their scientific enquiry and observation skills
By exploring a range of everyday examples, children begin to understand the difference between physical changes and chemical changes.
Examples of Reversible and Irreversible Changes
One of the best ways to help children understand this concept is by comparing examples side by side.
Reversible Changes
- Melting butter
- Freezing water
- Dissolving salt in water
- Stretching an elastic band
- Inflating a balloon
Irreversible Changes
- Burning toast
- Cooking pasta
- Baking biscuits
- Rusting metal
- Mixing vinegar and bicarbonate of soda
Encouraging children to explain why a change is reversible or irreversible helps them develop deeper scientific understanding.
Investigating Reversible and Irreversible Changes
Practical investigations make this topic memorable and engaging.
Children could:
- Observe ice melting and refreezing
- Investigate which substances dissolve in water
- Explore evaporation and condensation
- Compare raw and cooked foods
- Test chemical reactions using safe household materials
These activities provide opportunities for children to make predictions, record observations and draw conclusions based on evidence.
Properties and Changes of Materials Lesson Pack
If you're looking for ready-to-teach resources for reversible and irreversible changes KS2, our Properties and Changes of Materials Year 5 lesson pack includes a dedicated lesson exploring how materials change and whether those changes can be reversed.
Children investigate a range of everyday examples, sort changes into reversible and irreversible categories, and explain their reasoning using scientific vocabulary. The lesson includes ready-made teaching slides, differentiated activities, worksheets and teacher guidance to save valuable planning time.
Frequently Asked Questions
What is a reversible change?
A reversible change is a change that can be undone so that the material returns to its original state.
What is an irreversible change?
An irreversible change cannot be undone and often results in a new material being formed.
What year group learns about reversible and irreversible changes?
Reversible and irreversible changes Year 5 is taught as part of the Properties and Changes of Materials unit in KS2 science.
Is dissolving a reversible change?
Yes. In many cases, dissolving is reversible because the dissolved substance can be recovered by evaporating the liquid.
Why do children learn about reversible and irreversible changes?
Learning about reversible and irreversible changes helps children understand how materials behave, supports scientific enquiry skills and prepares them for more advanced science learning.
