20/08/2026
FORM 1 - CHEMISTRY
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During a practical lesson, a group of learners was given four substances: iron filings, sulphur powder, iron sulphide, and a mixture of sand and salt. The teacher asked the learners to investigate the substances and explain how they differ. The learners observed that iron and sulphur could be identified separately, while iron sulphide had properties different from both iron and sulphur. They also found that sand and salt could be separated using physical methods.
a) Explain how an element differs from a compound.
b) Describe how a mixture differs from a compound.
c) Examine the observations made by the learners and explain how they can be used to distinguish between iron and iron sulphide.
d) Describe how the mixture of sand and salt could be separated.
e) Examine why the properties of iron sulphide are different from those of iron and sulphur.
