Chemistry - Solid State Question with Solution | TestHub

${\rho }_{\text{unit cell }}(\mathrm{g}/\mathrm{cc})=\frac{\mathrm{Z}\times \mathrm{M}\cdot \mathrm{Mass}(\mathrm{g}/\mathrm{mol})}{{\mathrm{N}}_{\mathrm{A}}\left({\mathrm{mol}}^{-1}\right)\times (\mathrm{a}\mathrm{pm}{)}^3\times 10^{-30}}{\mathrm{Z}}_{\text{B.c.c }}=2$ or $5=\frac{2\times \text{ M.Mass }}{{\mathrm{N}}_{\mathrm{A}}\times (200{)}^3\times 10^{-30}}$ or M.Mass $=\frac{5\times 8\times {\mathrm{N}}_{\mathrm{A}}\times 10^{-24}}{2}=2{\mathrm{N}}_{\mathrm{A}}\times 10^{-23}$ Now, no. of moles in $100\mathrm{g}=\frac{100}{2{\mathrm{N}}_{\mathrm{A}}\times 10^{-23}}$ $\therefore$ no. of atoms $=\frac{100}{2{\mathrm{N}}_{\mathrm{A}}\times 10^{-23}}\times {\mathrm{N}}_{\mathrm{A}}=50\times 10^{23}=5.0\times 10^{24}$