Chemistry - Solid State Question with Solution | TestHub

$\mathrm{N}\mathrm{a}\mathrm{C}\mathrm{l}$has fcc structure.
In fcc lattice with ions in octahedral voids
${\text{r}}^{\text{+}}\text{+}{\text{r}}^{-}\text{=}\frac{\text{a}}{\text{2}}$
Where,$\text{a}\text{=}$edge length
${\text{r}}^{\text{+}}\text{=}\text{95}\text{pm, }{\text{r}}^{-}\text{=}\text{181}\text{pm }$
Edge length$\text{=}{\text{2r}}^{\text{+}}\text{+}{\text{2r}}^{-}$
$=(2\times 95+2\times 181)\text{pm}$
$\text{=}\text{190}\text{+}\text{362}\text{=}\text{552}\text{pm}$