Contents
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What can you recall?
identify
Recall and explain
Four substances are heated, then left to cool. In which row does the result after cooling prove that a new substance was made?
identify: name or select.
| Row | Before heating | After cooling |
|---|---|---|
| A | purple-black iodine crystals | purple-black crystals on the cool upper part of the tube |
| B | white glucose powder that dissolves in water | a black solid that does not dissolve in water |
| C | white titanium dioxide powder | white powder, after it turned pale yellow while hot |
| D | a grey lump of solder that conducts electricity | a flat strip of solder that still conducts electricity |
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Scope and sources
Cambridge IGCSE Chemistry 0620 · 2026–2028 v2 · Original learning materials.
Physical and chemical changes (6.1 Core 1): identifying physical and chemical changes and describing the difference in terms of whether any new substances have been made. Rates of reaction are in the next module, reversible reactions in 6.3 and the tests for gases in topic 12.
Apparatus, amounts and times in the experiment are illustrative. Real practical work follows a teacher-approved safety method.
Official Cambridge syllabus