Draw the resonance contributors for:

a. benzaldehyde

b. chlorobenzene.

A major resonance contributor is one that has the lowest energy. We can draw more than one Lewis structure for a molecule, differing only in the positions of the electrons. Each individual structure is called a resonance contributor.

a)

Aldehyde group withdraws electrons inductively as it is a ring deactivating and withdraws electrons by resonance. The resonance contributors for the benzaldehyde are as follows:

Resonance contributor for benzaldehyde

b)

Lone pair electrons of chlorine donate electrons by resonance. Chlorine deactivates the ring and directs ortho and para position as it withdraws electrons from the ring. The resonance contributors for the chlorobenzene are as follows:

Resonance contributor for chlorobenzene