Question

Which of the following order of ionic radii is correctly represented?

• A. \( H^- > H^+ > H \)
• B. \( Na^+ > F^- > O^{2-} \)
• C. \( F^- > O^{2-} > Na^+ \)
• D. \( Al^{3+} < Mg^{2+} < N^{3-} \)

Hint:

The ionic radius decreases with increasing positive charge and increases with increasing negative charge for ions with the same electron configuration.

Answer 1

The Correct Option is D

For ions sharing the same electron configuration, ionic radius shrinks as the ionic charge increases. The order is: - \( Al^{3+} \) exhibits the smallest ionic radius because of its 3+ charge. This is succeeded by \( Mg^{2+} \) (2+ charge), and finally \( N^{3-} \) (3- charge), which has the largest radius due to its negative charge. The correct sequence is therefore \( Al^{3+} < Mg^{2+} < N^{3-} \).