Question

the radius of a particle is 10pm. The unit cell has 74% packing efficiency. Calculate the volume of the unit cell​

Answer 1

Answer:

The edge length or side of the cube be 'a', and the radius of each particle be 'r'.

a=2r

Volume of cube =a

3

(2r)

3

=8r

3

In simple cube, each unit cell has only one sphere,

Volume of sphere =

3

4

πr

3

Packing efficiency

Volume of the cube

Volume if a sphere

×100%

=

8r

3

4

/3

πr

3

×100=52.4%.