Question

Which of the following ion has smallest ionic radius?

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

Lets calculate the number of electrons :

$K^{+}\to 18electrons$

$C{a}^{2+}\to 18electrons$

$T{i}^{3+}\to 18electrons$

$T{i}^{4+}\to 18electrons$

So, therefore, they all are isoelectronic species.

What do we know about isoelectronic species?

Higher the ionic charge on the atom more will be the ionic radius.