See the explanation below for the description of each.
Work Step by Step
a) The electron has a poor carbon atom that acts as an electrophile. b) CH3S- is a nucleophile because of the sulfur single pair of electrons c) C4H6N2 is a nucleophile because of the single-pair electrons of nitrogen. d) CH3CHO is both a nucleophile and an electrophile because of its polar bond between carbon and oxygen.