CAIE A Level Chemistry 9701 · Chemical energetics
The first electron affinities of oxygen and sulfur are and respectively.
Compare these two values in terms of the relative ease of adding an electron to a gaseous atom, and explain the difference in terms of atomic radius and electron shielding.
7 marks, so the mark scheme is looking for about 7 separate creditworthy points. Making the same point twice in different words earns it once.
Compare means: Give similarities or differences between two things, and say which side each point belongs to. Write each point as a pair, for example: A is X, whereas B is Y. Two separate descriptions rarely earn the marks.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.