CAIE IGCSE Chemistry Physical and Chemical Changes
Practise distinguishing physical and chemical changes from reversibility or new substances and recognising thermal decomposition from equations and observations.
- Syllabus
- 2026–2028
- Topic
- 6.1
- Level
- —
Practise distinguishing physical and chemical changes from reversibility or new substances and recognising thermal decomposition from equations and observations.
Limestone rock is mainly calcium carbonate, CaCO3.
The 'limestone cycle' is shown. Each step is numbered.

Which step involves a physical change?
(step) 3