Question:
Consider the elements $\mathrm{Mg}, \mathrm{Al}, \mathrm{S}, \mathrm{P}$ and $\mathrm{Si}$, the correct increasing order of their first ionization enthalpy is:
Correct Option: 1
Solution:
Order of IE, in $3^{\text {rd }}$ period is
$\mathrm{Na}<\mathrm{Mg}>\mathrm{Al}<\mathrm{Si}<\mathrm{P}>\mathrm{S}<\mathrm{Cl}<\mathrm{Ar}$
$\mathrm{Na}<\mathrm{Al}<\mathrm{Mg}<\mathrm{Si}<\mathrm{S}<\mathrm{P}<\mathrm{Cl}<\mathrm{Ar}$