Question

The ionic radii of $A^+$ and $B^-$ ions are $0.98 \times 10^{-10} \, m$ and ${1.81 \times 10^{-10} m}$. The coordination number of each ion in AB is :

• A. 4
• B. 8
• C. 2
• D. 6

Answer 1

Answer: (D)

6

Answer 2

Radius ratio = $\frac{0.98 \times 10^{-10}}{1.81 \times 10^{-10}} = 0.541$
it is in between 0.414 - 0.732
$\therefore$ C.N. is 6.