Question

Which of the following ions has the smallest radius?

• A. $T{i}^{2+}$
• B. $P{t}^{2+}$
• C. $N{i}^{2+}$
• D. $Z{n}^{2+}$

Answer 1

The correct option is C $N{i}^{2+}$

The ionic radius of $P{t}^{2+}$ is maximum as it has two more shells of electrons than other ions.

In the third transition series, the ionic radius of $Z{n}^{2+}$ is maximum due to interelectronic repulsion in 3d orbital because of completely filled d orbital.

As we move from left to right in a period, the atomic size decreases. The ionic radius of $N{i}^{2+}$ is minimum.