The charge/size ratio of a cation determines its polarizing power. Which one of the following sequences represents the increasing order of the polarizing power of the cationic species, `K^+,Ca^(2+), Mg^(2+), Be^(2+)`

Options

A. `Ca^(2+)ltMg^(2+)ltBe^(+)ltK^(+)`
B. `Mg^(2+)ltBe^(2+),ltK^(+)Ca^(2+)`
C. `Be^(2+)ltK^(+)ltCa^(2+)ltMg^(2+)`
D. `K^(+)ltCa^(2+)ltMg^(2+)ltBe^(2+)`

Answer

D

Explanation

Smaller the size and higher the charge more will be polarising power of cation. Since the order of the size of cation is `K^(+) gt Ca^(2+) gt Mg^(2+) gt Be^(2+)`. So the correct order of polarising power is `K^(+) lt Ca^(2+) lt Mg^(2+) lt Be^(2+)`