As gold atoms occupy all the corners of a unit cell, therefore, the number ofgold atoms per unit cell
= 8 x 1/8 = 1 atom
As cadmium atoms fit into the face centres, therefore, the
number of cadmium atoms per unit cell =6x1/2=3 atoms
.’. Ratio of gold (Au) and cadmium (Cd)= 1 : 3
Hence, formula for the given alloy is AuCd3.