In Group 14 elements, the stability of the higher oxidation state (+4) decreases and the stability of the lower oxidation state (+2) increases down the group due to the inert pair effect. For tin (Sn), the +4 state is more stable than +2, so Sn2+ readily loses two electrons to form Sn4+, acting as a reducing agent. For lead (Pb), the +2 state is highly stable compared to +4 due to a strong inert pair effect, meaning Pb4+ easily gains two electrons to form Pb2+, thus acting as a strong oxidizing agent.