Chromium metal crystallizes as a body-centered cubic lattice. If the atomic radius of Cr is 1.25 angstroms, what is the density of Cr metal in g/cm3?

To determine
the density of the unit cell, we need to find the mass of the unit cell and the volume of the
unit cell.  A body centered cubic unit cell contains a total of 2 atoms; one in the middle (i.e.
the body centered) and there are 8 at each corner each of which contributes 1/8 to the number of
atoms. 

We need to find the mass of the unit cell which we've already
determined contains two atoms.  We...