Question

The ionic radii for $N{a}^{+}$ and $B{r}^{-}$ ions are $1.012$ nm and $1.973$ nm respectively. What coordination number of $N{a}^{+}$ is predicted on the basis of the radii ratio, $\frac{r_{+}}{r_{-}}$ ?

• A. $6$
• B. $8$
• C. $4$
• D. $2$

Answer 1

The correct option is A $6$

The radius ratio, $\frac{r_{+}}{r_{-}}=\frac{1.012}{1.973}=0.513$

Hence, the coordination number of $N{a}^{+}$ is $6$.