(v); Due to the inert pair effect, the lower oxidation state, i.e. +2, is more stable than the higher one while travelling from top to bottom in the group.

As a result of the inert pair effect, Pb has a stable oxidation state of +2 rather than +4. Pb4+ will be transformed to Pb2+ by receiving two electrons. The inert pair effect is relatively weak in Sn, and the +4 oxidation state is more persistent than the +2.

(vi); Because fluorine has a relatively tiny size, the electrons in the 2p orbital are repelled by each other. As a result, the electron exiting the orbital does not encounter as much pull from the nucleus, resulting in a lower negative electron gain enthalpy for fluorine than for chl.