We know that in end-centred cubic unit cell, 8 atoms are located on 8 corners of the cube and 1 atom each is present on two opposite faces of the cube.
Atoms in end-centred cubic unit cell
- 8 atoms are present on 8 corners, where each atom contributes 1/8th portion of the cell
- 2 atoms are present at the centre of the cell, where each atom contributes 1/2 portion of the cell
Total atoms present in end centred cubic cell
Number of atoms at the corners + Number of atoms at the centre
Number of atoms in an end centred cubic unit cell=
8×1/8 + 2 x ½ = 2 atoms
Hence total atoms present in end centred cubic cell= 2 atoms
Answer
Two atoms are present in end centred cubic unit cell.