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GCSE Chemistry · key term
A change in state or form in which no new substance is produced and the chemical identity of the substance remains the same.
Used by Edexcel and OCR
Specification 2.2, 8.20 · Paper 1, Paper 2
Revise: Interconversions Between StatesA change of state is a physical change. The particles become arranged and move differently, but their chemical identity does not change.
A change between physical states in which no new substance is produced.
Specification C1.1b · Paper 1 (Foundation), Paper 3 (Higher)
A change in which no new substance is formed; the particles keep their chemical identity although their arrangement, movement, spacing or state may change.
Revise: Physical vs Chemical ChangesIn a physical change, no new substance forms: the original particles retain their chemical identity. In a chemical change, atoms or ions are rearranged so that one or more new substances form.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
A change in state or form in which the chemical identity of each substance remains the same and no new substance forms.
Revise: The particle modelA change of state is a physical change because no new substance is produced. The material may look and behave differently, but its chemical identity is unchanged. Melting wax and condensing water vapour are physical changes.
Use “physical change” and explain it with “no new substance is formed”. Saying only that the change is reversible is not a complete distinction.
In a particle-diagram question, track the types and combinations of particles. A changed spacing or arrangement indicates a physical change; atoms joined or grouped differently indicate a chemical change.
Do not say that particles themselves expand during a physical change. Their movement, energy, spacing or arrangement may change.
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