Question

What is the edge length of a face-centered cubic unit cell made up of atoms having a radius of 144 pm?

Answer 1

Answer:

407pm is the edge length of the cubic unit cell

Explanation:

In a Face-centered cubic unit you can use Pythagoras theorem to relate edge length with atomic radius (As you can see in the picture), thus:

e²+e² = (4r)²

2e² = 16r²

e = √8 r

If the atomic radius of the atom is 144pm:

e = √8 ×144pm

e = 407ppm

407pm is the edge length of the cubic unit cell