What is the edge length of a face-centered cubic unit cell that is made of of atoms, each with a radius of 154 pm

The edge length of a face-centered cubic unit cell is 435.6 pm.

Explanation:

In a face-centered cubic unit cell, each of the eight corners is occupied by one atom and each of the six faces is occupied by a single atom.

Hence, the number of atoms in an FCC unit cell is:

In a face-centered cubic unit cell, to find the edge length we need to use Pythagorean Theorem:

    (1)

Where:

a: is the edge length

R: is the radius of each atom = 154 pm      

By solving equation (1) for "a" we have:

Therefore, the edge length of a face-centered cubic unit cell is 435.6 pm.   

I hope it helps you!

dynamic equilibrium is the answer.