Question

The set representing the correct order of ionic radius is:

• A. $Na^{+}>Li^{+}>Mg^{2 +}>Be^{2 +}$
• B. $Li^{+}>Na^{+}>Mg^{2 +}>Be^{2 +}$
• C. $Mg^{2 +}>Be^{2 +}>Li^{+}>Na^{+}$
• D. $Li^{+}>Be^{2 +}>Na^{+}>Mg^{2 +}$

Answer 1

Answer: (A)

As on moving left to right across the period radius or ionic radius decreases and on moving down the group it increases so following this periodic trends of size the correct order is $\left(Na\right)^{+}\left(\right.1.02\overset{^\circ }{A}\left.\right)>\left(Li\right)^{+}\left(\right.0.74\overset{^\circ }{A}\left.\right)>\left(Mg\right)^{2 +}\left(\right.0.72\overset{^\circ }{A}\left.\right)>\left(Be\right)^{2 +}\left(\right.0.27\overset{^\circ }{A}\left.\right)$