An element has a face-centered cubic (fcc) structure with a cell edge of $a$. The distance between the centres of two nearest tetrahedral voids in the lattice is (1) $\frac{a}{2}$ (2) $\frac{3}{2}a$ (3) $a$ (4) $\sqrt{2}\,a$
An element has a face-centered cubic (fcc) structure with a cell edge of $a$. The distance between the centres of two nearest tetrahedral voids in the lattice is\\
(1) $\frac{a}{2}$\\
(2) $\frac{3}{2}a$\\
(3) $a$\\
(4) $\sqrt{2}\,a$