Question

calculate the mass of the unit cell of copper
crystal if it has fcc lattice and atomic mass =
63.5​

Answer 1

Answer:

Atomic mass of copper = 63.5. or Copper crystallises into a fcc lattice, its edge length is 3.62×10-8 cm. Calculate the dinsity of copper (atomic mass of Cu= 63.5 u, NA=6.022×1023mol-1)

Answer 2

Answer:

Theoretical density of a crystal is given by ρ=

N

A

a

3

nM

g/cm

3

Given, M=63.5 g ; ρ=8.93 g/cm

3

For FCC, n=4

⇒a

3

=

6.022×10

23

×8.93

4×63.5

⇒a=(

6.022×10

23

×8.93

4×63.5

)

1/3

=3.6×10

−8

cm

Now, if r is radius of copper atom, then in FCC,

r=

2

2

a

r=

2

2

3.6

×10

−8

cm=127.8 pm

Explanation:

may this help for u