I`ve started reading up and practically making various resonance structures of various molecules. Though in the book I am reading I have only been subsituted with the information that it can be very neccessary for chemical mechanics later on in the book. Is this correct? Also, the book doesn`t seem to tell me why they are of ANY practical purpose? I understand this is way to represent the same molecule but bonded differently, because of the delocalized electrons. Like i.e. benzene. However, I don`t seem to be able to get why they are neccessary to know within organic chemistry and I am unable to find an answer to this question on the world wide web. What practical purpose does it serve? Thanks.