CAIE A Level Chemistry 9701 · States of matter
A technician tests two crystalline samples of pure carbon, A and B, at room temperature.
Sample A is black, slippery and flakes easily. It conducts electricity when connected in a circuit.
Sample B is colourless, very hard and does not conduct electricity when connected in the same circuit.
Suggest, in terms of structure and bonding, why the two samples differ in electrical conductivity.
4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.
Suggest means: Apply what you know to an unfamiliar situation. There may be more than one acceptable answer. Reason from the principle you have learned to the new context, and say which principle you are using.
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