Question

Silver is a metal commonly used in jewelry and photography. It crystallizes with a FCC unit cell 0.407 nm on an edge. What is the theoretical density (g/mL) of silver in g/cm3 if its atomic weight is 107.87 g/mol?

Answer 1

The number of atoms in the unit cell of an FCC structure , n=4

$a=0.407nm=0.407\times 10^{-7}cm$

Avogadro number, $N_A=6.022\times 10^{23}$

$M=atomic mass=107.87g/mol.$

density of silver $=\frac{n\times M}{N_A \times a^3}=\frac{4\times 107.87}{6.022\times 10^{23} \times (0.407\times 10^{-7})^3}=10.62g/cm^3$