Question

Cu crystallizes in fcc unit cell with edge length of 495pm. What is the radius of Cu atom ?​

Answer 1

Answer:

For fcc unit cell :

a = (2√2)*r

r = a/(2√2)

= 495/(2√2) = 175 pm

Hope it will be helpful ✌️

Answer 2

Explanation:

As given that copper crystallizes is FCC lattice (Face centred cubic). In FCC atoms are present on the corners of the cubic, unit cell as well as on the face centres of each face.

The atoms on the face diagonal will be touching each other. Let, the radius of the atom be r and edge length of the cube be a.

Face diagonal of cube =

2

a

⇒r+2r+r=

2

a

⇒r=

4

2

a

=

2

2

a

=

2

2

361

pm=128 pm