Every atom or ion that forms an fcc unit cell is surrounded by

Options

A. Six `OVs` and eight `TVs`.
B. Eight `OVs` and Six `TVs`.
C. Six `OVs` and six `TVs`.
D. Eight `OVs` and four `TVs`.

Answer

A

Explanation

Look at corner at atom of fcc unit cell. A corner aom can support `8` unit cell. In each cube, at a distance of `sqrt(3)a//4` from corner atom, therre is a tetrahedral void, it implied each atom is surrounded by eight tetrahedral voids. At the centre of edge, there is an octahedral void. Each corner can support six edges and hence it is surrounded by six octahedral voids.