, 7.4 Formal charges and resonance
Formal Charge
• The formal charge of an atom in a molecule is the hypothetical char
the atom would have if we could redistribute the electrons in the bo
evenly between the atoms.
• # valence shell electrons (free atom) − # lone pair electrons
• − ½ # bonding electrons
• The formal charge is hypothetical and not the actual charge on an at
• Formal charges are useful for predicting molecular structure, as we
see.