Question

An ionic crystal lattice has $\frac{r^{+}}{r^{-}}$ radius ratio of $0.320$, its co-ordination number is:

• A. $3$
• B. $4$
• C. $6$
• D. $8$

Answer 1

Answer: (B)

$4$

According to radius ratio rule, an ionic crystal lattice with $\frac{r^{+}}{r^{-}}$ in the range $0.225to0.414$ has co-ordination number 4.

Therefore, option B is correct.