The correct order of the first ionization enthalpy is

How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?

The ionization energy of nitrogen is larger than that of oxygen because of

Which of the following statements is correct regarding the first $(I)$ and second $(II)$ ionization enthalpies of sodium $(Na)$ and magnesium $(Mg)$?

Match List-$I$ with List-$II$:

List-$I$ (Electronic configuration)	List-$II$ ($\Delta_{i}H$ in $kJ\ mol^{-1}$)
$(a)$ $1s^{2} 2s^{2}$	$(i)$ $801$
$(b)$ $1s^{2} 2s^{2} 2p^{4}$	$(ii)$ $899$
$(c)$ $1s^{2} 2s^{2} 2p^{3}$	$(iii)$ $1314$
$(d)$ $1s^{2} 2s^{2} 2p^{1}$	$(iv)$ $1402$

Choose the most appropriate answer from the options given below:

Arrange $S, P, As$ in order of increasing ionisation energy.