The electronic configuration with the highest ionization enthalpy is: [Ne]3s²3p¹, [Ar]3d¹⁰4s²4p³, [Ne]3s²3p³, [Ne]3s²3p²

The electronic configuration with the highest ionization enthalpy is [Ne]3s²3p³. On moving down the group, the ionization enthalpy decreases. In a period, on moving from left to right, the ionization enthalpy increases.