Question

Match the following unit cell with number of atoms present in the unit cell

• A. 1
• B. 4
• C. 2

Answer 1

For simple cubic unit cell,8 atoms on its corners, the total number of atoms in one unit cell is
$8\mathrm{corners}\times \frac{1}{8}percorneratom=1$For body centered cubic unit cell, 8 atoms in its corner and 1 atom in the centre.
$1\mathrm{body}\mathrm{centered}\mathrm{atom}+8\mathrm{corner}\times \frac{1}{8}\mathrm{per}\mathrm{corner}\mathrm{atom}=2$For face centered cubic unit cell, 8 atoms in its corner,6 face centered atoms shared by 2 unit cell
$8\mathrm{corners}\times \frac{1}{8}\mathrm{per}\mathrm{corner}\mathrm{atom}=16\mathrm{atoms}\times \frac{1}{2}\mathrm{atoms}\mathrm{per}\mathrm{unit}\mathrm{cell}=31+3=4$