CAIE A Level Chemistry 9701 · Chemical energetics
The first electron affinities of the Group 16 elements are all exothermic, but the values become less exothermic down the group.
Describe and explain, in terms of the factors affecting electron affinity, why the first electron affinities of Group 16 elements become less exothermic down the group.
6 marks, so the mark scheme is looking for about 6 separate creditworthy points. Making the same point twice in different words earns it once.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
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