Question

-] Distinguish between face centred and end centred unit cell.
(Marks 2)​

Answer 1

Answer:

Explanation:

In face centred cubic structure 8 atoms are located at the corner and 6 atoms at each centre of the face

Total contribution of atoms will be (8×1/8)+ (6+1/2) = 1 + 3 = 4

While in end centred 8 atoms are located at the corner and 2 atoms are located on the centre of two parallel side of the cube

Total contribution of atoms will be (8 × 1/8) + (2 × 1/2) = 1 + 1 = 2

Answer 2

Answer:

Explanation:(Face-centred)---such a unit cell contains one constituent particle present at the centre of each face , besides the ones that are at its corner.

(End- centred unit cell)--- In such a unit cell , one constituent particle is present at the centre of any two opposite faces besides the ones present at its corner.