Question

The correct orders of ionization enthalpies of the given elements are \[ \begin{aligned} \text{I. }& \mathrm{Li}>\mathrm{B}>\mathrm{Be}>\mathrm{Mg} \text{II. }& \mathrm{P}>\mathrm{Mg}>\mathrm{Al}>\mathrm{Na} \text{III. }& \mathrm{O}>\mathrm{F}>\mathrm{N}>\mathrm{C} \end{aligned} \] The correct answer is

• A. I, II, III
• B. II, III only
• C. I, III only
• D. I, II only

Hint:

Remember the important exceptions in ionization enthalpy: \[ \boxed{\mathrm{Be}>\mathrm{B}} \] and \[ \boxed{\mathrm{N}>\mathrm{O}} \] due to the stability of filled and half-filled subshells.

Answer 1

The Correct Option is C