Aluminium metal has face centred cubic (f.c.c.) structure. The number of 'Al' atoms per unit cell of the lattice is

Question

Aluminium metal has face centred cubic (f.c.c.) structure. The number of 'Al' atoms per unit cell of the lattice is (A) 2 (B) 1 (C) 4 (D) 6

Tardigrade Admin · Accepted Answer

In a unit cell there are 8 corners and 6 faces. Since each comer of the unit cell is shared by eight unit cells, and each face is shared by two unit cells, the number of points per face unit cell Z = 8 × (1/8) +6 × + (1/2) = 1 + 3 = 4

Q. Aluminium metal has face centred cubic (f.c.c.) structure. The number of $^{'} A l^{'}$ atoms per unit cell of the lattice is

2

1

4

6

In a unit cell there are $8$ corners and $6$ faces.
Since each comer of the unit cell is shared by eight unit cells, and each face is shared by two unit cells, the number of points per face unit cell
$Z = 8 \times \frac{1}{8} + 6 \times + \frac{1}{2}$
$= 1 + 3 = 4$

Q. Aluminium metal has face centred cubic (f.c.c.) structure. The number of ′Al′ atoms per unit cell of the lattice is

2

1

4

6

In a unit cell there are 8 corners and 6 faces. Since each comer of the unit cell is shared by eight unit cells, and each face is shared by two unit cells, the number of points per face unit cell Z=8×81​+6×+21​ =1+3=4

Q. Aluminium metal has face centred cubic (f.c.c.) structure. The number of $^{'} A l^{'}$ atoms per unit cell of the lattice is

In a unit cell there are $8$ corners and $6$ faces.
Since each comer of the unit cell is shared by eight unit cells, and each face is shared by two unit cells, the number of points per face unit cell
$Z = 8 \times \frac{1}{8} + 6 \times + \frac{1}{2}$
$= 1 + 3 = 4$