CAIE A Level Chemistry 9701 · Group 17
Chlorine, bromine and iodine are molecular elements. Their boiling points are –34 °C, 59 °C and 184 °C respectively.
Suggest, in terms of the structure and bonding of the molecules, why the boiling points increase from chlorine to iodine.
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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