Question

Select the correct order of ionic radii :

• A. $T{i}^{2+}>T{i}^{3+}>T{i}^{4+}$
• B. $T{i}^{4+}>T{i}^{2+}>T{i}^{3+}$
• C. $T{i}^{3+}>T{i}^{2+}>T{i}^{4+}$
• D. $T{i}^{4+}>T{i}^{3+}>T{i}^{2+}$

Answer 1

The correct option is A $T{i}^{2+}>T{i}^{3+}>T{i}^{4+}$

$T{i}^{2+}$ has 20 electrons.Outermost shell is $n=4$.

$T{i}^{3+}$ has 19 electrons.Outermost shell is $n=4$.

$T{i}^{4+}$ has 18 electrons.Outermost shell is $n=3$.

Hence $T{i}^{4+}$ is the smallest. $T{i}^{2+}>T{i}^{3+}$ because there is less number of electrons, hence greater nuclear charge and therefore the electrons are pulled closer to the nucleus.

Hence. option A is the right answer.