Chemistry - Solid State Question with Solution | TestHub

Effective number of remaining$\mathrm{C}{\mathrm{l}}^{-}=4-\left[2\times \frac{1}{8}+\frac{1}{2}\right]=\frac{13}{4}$
Effective number of$\mathrm{N}{\mathrm{a}}^{+}=4$
Packing fraction$=\frac{\text{Occupied volume}}{\text{Total volume}}$
$=\frac{\frac{13}{4}\times \frac{4}{3}\mathrm{\pi }{\mathrm{r}}_{-}^3+4\times \frac{4}{3}\mathrm{\pi }{\mathrm{r}}_{+}^3}{8({\mathrm{r}}_{+}+{\mathrm{r}}_{-}{)}^3}$
$\frac{\frac{13}{3}\mathrm{\pi }{\mathrm{r}}_{-}^3+\frac{16}{3}\mathrm{\pi }{\mathrm{r}}_{+}^3}{8({\mathrm{r}}_{+}+{\mathrm{r}}_{-}{)}^3}$