Q. The charge/size ratio of a cation determines its polarising power. Which one of the following sequences represents the increasing order of the polarising power of the cationic species, $K^{+},Ca^{2 +},Mg^{2 +},Be^{2 +}$?
A) $Mg^{2 +} < Be^{2 +} < K^{+} < Ca^{2 +}$
B) $Be^{2 +} < K^{+} < Ca^{2 +} < Mg^{2 +}$
C) $K^{+} < Ca^{2 +} < Mg^{2 +} < Be^{2 +}$
D) $Ca^{2 +} < Mg^{2 +} < Be^{2 +} < K^{+}$
Explanation
(c)
Higher the charge/size ratio, more is the polarising power.
$K^{+} < Ca^{2 +} < Mg^{2 +} < Be^{2 +}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.