Question

Aluminium crystallises in a cubic close-packed structure. Its metallic radius is 175 pm. What is the length of the side of the unit cell?​

Answer 1

Answer:

It is given that aluminum crystallises in a cubic closed packed structure.

Its metallic radius is 125 pm.

(i) For cubic close-packed structure

a=2

2

r=2

2

×125=354 pm

Here, a is the edge length of the unit cell and r is the atomic radius.

(ii) Volume of one unit cell

=a

3

=(354 pm)

3

=4.4×10

−23

cm

3

(1 pm=10

−10

cm)

Number of unit cells in 1.00cm

3

=

4.4×10

−23

cm

3

1.00cm

3

=2.27×10

22

Explanation:

Hope it will help you