• # question_answer 70)   In which of the following options, order of arrangement does not agree the variation of property indicated against it? (a) $A{{l}^{3+}}<M{{g}^{2+}}<N{{a}^{+}}<{{F}^{-}}$ (increasing ionic size) (b) $B\text{ }<\text{ }C\text{ }<\text{ }N\text{ }<\text{ O}$ (increasing first ionisation enthalpy) (c) $I\text{ }<\text{ }Br\text{ }<\text{ }Cl\text{ }<\text{ }F$ (increasing electron gain enthalpy) (d) $I\text{ }<\text{ }Br\text{ }<\text{ }Cl\text{ }<\text{ }F$ (increasing metallic radius)

(b, c) For increasing first ionisation enthalpy, the order should be: $B\text{ }<\text{ }C\text{ }<\text{ }O\text{ }<\text{ }N.$                 For increasing electron gain enthalpy, the order should be: $I\text{ }<\text{ }Br\text{ }<\text{ }F\text{ }<\text{ }Cl.$