The first ionization enthalpy of \( \mathrm{Na} \), \( \mathrm{Mg} \) an \( \mathrm{Si} \), respectively, are: \( 496 \) and \( 737 \) and \( 786 \) \( \mathrm{kJ \, mol^{-1}} \). The first ionization enthalpy (\( \mathrm{kJ \, mol^{-1}} \)) of \( \mathrm{Al} \) is:
