Final answer:
The bond enthalpy of an N-N bond with resonance forms consisting of equal contributions from single and double bonds can be predicted as the average of the bond enthalpies of single N-N bonds and double N-N bonds.
Step-by-step explanation:
When a molecule has resonance forms that include equal contributions from single and double bonds, the bond enthalpy can be predicted as an average of the bond enthalpies of the single and double bonds.
In the case of an N-N bond, the bond enthalpy would be the average of the bond enthalpy for a single N-N bond and the bond enthalpy for a double N-N bond.