The first ionization enthalpy (∆_i H ) values of the third-period elements, Na, Mg, and Si are respectively 496, 737, and 786 kJ mol^–1. The first ∆_i H value for Al will be^-

1. Less than 496 kJ mol^–1
2. Less than 737 kJ mol^–1
3. In between 737 kJ mol^–1 and 786 kJ mol^-1
4. Cannot predict