Chemistry > Inorganic Chemistry > Classification Of Elements And Periodicity

$\text{Al}^{3+} < \text{Mg}^{2+} < \text{Na}^+ < \text{F}^- :$ Increasing ionic size

$\text{I} < \text{Br} < \text{F} < \text{Cl} :$ Increasing electron gain enthalpy (with negative sign)

$\text{Li} < \text{Na} < \text{K} < \text{Rb} :$ Increasing metallic radius

$\text{B} < \text{C} < \text{N} < \text{O} :$ Increasing first ionization enthalpy