Question

Which of the following ions has the smallest radius?

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

Answer 1

Answer: (C)

$r_n\propto \frac{1}{Z}$
$T{i}^{2+}(22)>\underset{\text{smaller}}{N{i}^{2+}(28)}$
$P{t}^{2+}(5d$-series )
$Z{r}^{2+}(4d$ -series )
Have higher number of orbits
Hence, larger size