# Copper has the fcc crystal structure.Assuming an atomic radius of 130pm for copper atom (Cu = 63.54).What is the volume of the unit cell?

$\begin{array}{1 1}4.94\times 10^{-23}cm^3\\3.94\times 10^{-23}cm^3\\2.94\times 10^{-23}cm^3\\1.94\times 10^{-23}cm^3\end{array}$

Volume of unit cell $a^3=\large\frac{n\times M}{N_A \times \rho}$
$\Rightarrow \large\frac{4\times 63.54}{6.023\times 10^{23}\times 8.54}$$cm^3$
$\Rightarrow 4.94\times 10^{-23}cm^3$