CAIE A Level Chemistry 9701 · Chemistry of transition elements
Manganese forms stable ions in oxidation states +2, +3, +4, +6 and +7. The 3d and 4s sub-shells in manganese atoms have similar energies.
Compare the behaviour of manganese with that of a typical s-block element such as calcium, which has only one common oxidation state, in terms of:
(a) the origin of variable oxidation states;
(b) the ability to act as a catalyst;
(c) the ability to form complex ions.
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.
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.
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