The vacant space in bcc lattice unit cell is:

Step-by-step solution

Packing efficiency of BCC unit cell - Packing efficiency of BCC unit cell is given by, ( aligned & Packing efficiency = Volume occupied by two spheres 100 Volume of unit cell & = 2 4 3 r^3 100 a^3 & =68 % aligned ) - The ( % ) volume occupied by atoms in a unit cell is (68 % ) % Vacant space in BCC unit cell - % vacant space is given by, ( aligned & % Vacant space =100- % of the volume occupied by atoms & =100-68 & =32 % aligned ) - % Vacant space is (32 % )