In a compound with resonance structures, the actual structure of the molecule is the average of all resonance structures for the compound. true false

The answer to this question is TRUE.

Rather than simply believing this statement, you can find evidence to support this claim. We can look at the length of various carbon-carbon bond lengths.

In the molecule ethane, we have H₃C-CH₃, with a C-C single bond length of 154 pm.
In the molecule ethene, we have H₂C=CH₂, with a C=C double bond length of 133 pm.

We see from this data that a double bond is shorter than a single bond. Now if we look at the structure of benzene:
      H        H
       C  =  C
      /           \
H-C            C-H
      \\         //
       C --- C
      H        H

It appears that there are three C=C double bonds and three C-C single bonds. So you would expect different bond lengths between the double and single bonds. However, what we actually find is that every C-C bond is the same length of 140 pm. This is due to resonance, therefore, every C-C bond is actually an average of the double bond character and single bond character each bond experiences which gives us a value of 140 pm which is longer than a traditional C=C bond and shorter than a traditional C-C bond.