Question

As a solid, Cr adopts a body-centered cubic unit cell. How many unit cells are present per cubic centimeter of Cr?

Answer 1

um the only way i see to solve this is to find how many atoms you have in on cubic centimetre, then since you know it has a bcc shape, use that to derive the amount of unit cells?

Answer 2

You can use the fact that in a bcc unit cell, the cell width equals 4/sqrt(3) times the radius of the atom, and that the radius of Cr ( http://www.webelements.com/) is 127pm.