Final answer:
Experimental bond angles cannot be used to determine which resonance structure is more important since these structures are hypothetical and represent delocalized electrons. The actual electronic structure of a molecule like benzene is a hybrid of all valid resonance structures.
Step-by-step explanation:
It is not possible to use experimental bond angles to determine which resonance structure is more important. The reason is that resonance structures are a way to represent a molecule that has delocalized electrons, which are electrons spread over several atoms.
These different structures do not represent different static situations but are instead hypothetical constructs that contribute to the actual electronic structure of the molecule, which is a weighted hybrid of all valid resonance structures.
This hybrid reflects the delocalized nature of the electrons. For example, in the molecule benzene, neither resonance structure fully describes the electrons in the bonds since they are delocalized throughout the ring, exhibiting bond lengths that are intermediate between single and double bonds.