Consider the metal cesium, whose atoms are 0.265 nanometers in radius (for metallic bonds) ... the largest of all the elements. What is the length, in nanometers, of the empty space between atoms that reside along <100> directions in a BCC crystal of Cs metal?

The edge length of the empty space between atoms that reside along [100] directions in a BCC crystal of Cs metal is 0.612 nanometers

Explanation:

For Body centered cubic structure (BCC) crystal in direction [100], the edge length of unit cell is calculated with the formula below;

X =

Where;

X is the edge length of the empty space between atoms

R is the radius of the cesium atom = 0.265 nanometers

X = (4*0.265)/(√3)

X = 0.612 nanometers

Therefore, the edge length of the empty space between atoms that reside along [100] directions in a BCC crystal of Cs metal is 0.612 nanometers