C Curriculum Explorer
Science·Matter & Materials·conceptual

Irreversible Changes

Explain that some changes result in the formation of new materials and are not usually reversible, such as burning, rusting, and reactions with acid

Suggested ages 9–11

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Learning journey

Your child is exploring how materials behave and change — investigating which substances dissolve in water, learning to separate mixtures, and distinguishing between changes that can be reversed and those that create entirely new materials.

Evidence of understanding

  • Define an irreversible change as one that creates new materials that cannot be changed back
  • Give at least three examples: burning, rusting, mixing bicarbonate of soda with vinegar
  • Describe observable signs of irreversible change: gas produced, colour change, heat given off, new substance formed

Assessment prompt

Can Irreversible Changes explain why you can't un-burn a piece of toast or turn rust back into shiny iron, because a completely new material has been made?

Standards alignment

5-PS1-4US · ngss-k5

5-PS1-4

Next Generation Science Standards (NGSS) K-5

Y5.Sci.PCM.6GB · uk-nc-2013

Irreversible changes and new materials

The national curriculum in England: Key stages 1 and 2 framework document · Key Stage 2