Read before you solve · 2 min
Read Reversible irreversible and reaction types
This SOF ISO pattern tests classify changes. Read the condition carefully, then use the method below before you solve.
ISO · Matter and Chemical Changes · 1 linked question · 100% coverage
Know this first
Chemistry questions first require the material, particles or reaction condition to be identified before a formula or rule is selected.
Observation · What the stem states or showsCondition · The factor that controls the change
Study deeper: Class 7 Science · Matter and Chemical Changes
Find the tested idea
Identify the material, change or observable property first; this decides the scientific rule to use.
Work from the evidence
Use the experiment or stated observation as evidence. Compare each option with the property, particle model or reaction condition in the stem.
Verify before choosing
Use the wording, diagram and units exactly as given. Select an option only after it satisfies every stated condition.
OlympIQ exam lens
- ✓State the observed property.
- ✓Select the governing idea.
- ✓Test every claim against the evidence.
OlympIQ trap
Keep physical changes, chemical changes and everyday appearances separate.
Ready to try the pattern?
100% coverage across the linked question.
Practise the linked questionSign in to practise — your XP, streak and analysis update as you solve.