A metal crystallises in a face centred cubic structure. If the edge length of its unit cell is ‘a’, the closest approach between two atoms in metallic crystal will be :

Question

$\begin{array}{1 1} (1) \sqrt a \\ (2) \large\frac{a}{\sqrt 2} \\ (3) 2a \\ (4) 2 \sqrt 2 a \end{array}$

Comments

simple question ask something tough