EXERCISE 2.5 A nitrogen atom, with three 2p electrons, could have three unpaired electrons f ), or it could have one unpaired electron ( 1 + 1 a. Determine the number of electrons that could be exchanged in each case and the Coulombic and exchange energies. Which state would be lower in energy? b. A third possible state for a 2p configuration would be Determine its Coulombic and exchange energies, and compare the energy of this state with the energies determined in part a