Molecule has resonance if there are are more than one allowed arrangements of electrons.
Can’t move _________________________
In reality structure is a mix of the resonance structures.
Examples we’ll do in class NO 3
[HCO ] Back through N O
Look a the structures we drew.
How are the electrons really placed around the molecule, which one is “right”?
Equivalent structures, or structures with the same energy
Low energy structure contribute more than high energy structures.