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KS2 Science textbook

Chapter 7: Reversible and irreversible changes

  • Strand Properties and changes of materials
  • Level Year 5
  • Practice 83 questions with step-by-step solutions

National Curriculum for England, Key Stage 2 science, Year 5. Content: M5 demonstrate that dissolving, mixing and changes of state are reversible changes, M6 explain that some changes result in the formation of new materials, and that this kind of change is not usually reversible, including burning and the action of acid on bicarbonate of soda.

Open Year 5 chapter

By the end of this chapter you will be able to

  • Say which changes are reversible, such as melting and freezing, and dissolving
  • Explain why a change that makes a new material is usually not reversible
  • Describe what happens when an acid, such as vinegar, reacts with bicarbonate of soda
  • Use evidence, such as a gas or a new colour, to decide whether a change has made a new material
  • Sort changes into reversible and irreversible, and give a reason

You should already know

  • Solids, liquids and gases, and changes of state in the water cycle (Year 4 Science)
  • Solutions, and dissolving solids in water (Year 5 Science, Chapter 6)

Where this leads

  • The Earth, Sun and Moon (Year 5 Science, Chapter 8)
  • Forces, gravity and resistance (Year 5 Science, Chapter 9)

Lessons in this chapter

  1. 7.1 Reversible changes
  2. 7.2 Changes of state and mixing
  3. 7.3 Irreversible changes and new materials
  4. 7.4 Acid and bicarbonate of soda
  5. 7.5 Deciding whether a change is reversible
  6. Summary and key words
  7. Check-up and practice test questions

Read the whole chapter on one page (good for printing).