The coordination number of an `fcc` structure for a metal is `12`, since

Options

A. Each atoms touches four others in same layer , two in layer above and six in layer below .
B. Each atom touches four others in same layer , four in layer above and four in layer below .
C. Each atom touches six others in same layer , three in layer above and three in layer below .
D. Each atom touches eight other in same layer , two in layer above and two in layer below .

Answer

B

Explanation

Each atom touches 4 atoms in the same layer ,4 in above layer and 4 in layer below.