# Why aren't these two resonance structure same? [duplicate]

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Draw the resonance structures of Fluorobenzene.

In the solutions the structures below were given, I wonder why these structures are not just same. Both of these structures have a negative formal charge on the ortho position.

• Are the above structure of Fluorobenzene same ?

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• They are not "really" different, but there are two ortho carbons in fluorobenzene so you draw a resonance structure showing charge delocalization to each ortho carbon. There is also a third resonance structure with the charge on the para carbon - 3 resonance structures in all. – ron Feb 10 '17 at 17:56
• @ron Does that mean that when we draw resonance structures we aim to show all the different places where electron can delocalize ? does not matter if it is resonance structures are similar or different. – A---B Feb 10 '17 at 18:03
• Yes, that's correct. – ron Feb 10 '17 at 18:04
• @ron Thank you $\ddot \smile$. That instantly solved many of my questions about resonance theory. – A---B Feb 10 '17 at 18:05
• Simply - When you're drawing resonance structures you effectively number the atoms to break symmetry. – MaxW Feb 10 '17 at 18:11