For resonance forms of a molecule or ion, .
A) there cannot be more than two resonance structures for a given species
B) the observed structure is an average of the resonance forms
C) all the resonance structures are observed in various proportions
D) the same atoms need not be bonded to each other in all resonance forms
E) one always corresponds to the observed structure

Question

Quizplus · Accepted Answer

Resonance forms are theoretical structures that represent the delocalization of electrons in a molecule or ion. In reality, the molecule or ion exists as the average of all the resonance structures. In other words, the observed structure is a blend of all the resonance forms. Therefore, option B is the best choice. Options A and C are incorrect because there can be many resonance structures for a given species, and not all of them are observed in equal proportions. Option D is true since the atoms can be rearranged in resonance forms. Option E is not always true because the observed structure might not correspond to any specific resonance form.

For Resonance Forms of a Molecule or Ion