We have given that
Edge length of the unit cell
= 200 pm = 200 x 10–10 cm
Vol. of the unit cell
= (200 x 10–10 cm)3 = 8 x 10–24 cm3
Therefore, volume of the substance
= Vol. of unit cell x Vol. of 1 unit cell.
Since the element has a fcc unit cell, number of atoms per unit cell = 4.
Total number of atoms = Atoms/unit cell x number of unit cells.
= 24 x 1023atoms = 4
atoms/unit cell x No. of unit cells.
∴ No. of unit cells =
∴ Volume of the substance