What is or isn't a Resonance Structure?

[HoganFenster2E]

According to the solutions manual chapter three question 45, the boxed lewis structure in the attached image is not a resonance structure. Why not? it has 24 electrons and octets for all the atoms involved.

[904642541]

They have the same molecular formula and moreover the same number of electrons. However, the connectivity of the molecules is different (the double bond can be switched between the oxygen atoms).

[Chem_Mod]

Check your formal charges.. the bottom structure has Cl with a FC of +1. But we know that Cl is an electronegative atom (or it has a high ionization energy), so it will not give up its electrons to become positive. As a rule the halogens (group 17) will only make 1 bond!