Calculate the number of unit cells in 0.9 g metal if it forms bcc structure. $\left[\rho \times…
Calculate the number of unit cells in 0.9 g metal if it forms bcc structure. $\left[\rho \times \mathrm{a}^3=3 \times 10^{-22}\right.$ gram $]$
$\quad 1.0 \times 10^{21}$
$2.0 \times 10^{21}$
$3.0 \times 10^{21}$
$4.0 \times 10^{21}$
Solution
Number of unit cells in 0.9 g metal $=\frac{0.9}{\rho \times \mathrm{a}^3}$
$\begin{aligned}
& =\frac{0.9 \mathrm{~g}}{3 \times 10^{-22} \mathrm{~g}} \\
& =3 \times 10^{21}
\end{aligned}$