Chemistry - Solid State Question with Solution | TestHub

Edge length of the unit cell, $a=500\text{ pm}=500\times 10^{-12}\text{ m}=5\times 10^{-8}\text{ cm}$

Volume of one unit cell, $V=a^3=(5\times 10^{-8}{)}^3{\text{ cm}}^3=125\times 10^{-24}{\text{ cm}}^3$

Number of unit cells in $1{\text{ cm}}^3=\frac{\text{Total volume}}{\text{Volume of one unit cell}}$

Number of unit cells $=\frac{1}{125\times 10^{-24}}=\frac{1000\times 10^{21}}{125}=8.0\times 10^{21}$

Answer: $8.0\times 10^{21}$