Question

what is the total number of voids in cubic close packed lattice? metallic gold crystallises in fcc cubic lattice ,what is the number of units cell in 2gm of gold (au=197)
​

Answer 1

Answer:

=1.44×10

−8

cm

Explanation:

density of Gold = 19.3g/cm

3

density =

9

3

.NA

zM

19.3=

9

3

.6.022×10

23

4×197

9

3

=

6.022×10

23

×19.3

4×197

value of z=4

9

3

=6.78×10

−23

=4.077×10

−8

2

a=4

r

r=

4

2

9

=

4

2

×4.077×10

−8

=1.44×10

−8

cm