Question

Copper has density of 8.94 and crystallizes with the face-centered cubic unit cell. Calculate the radius of a copper atom.

Answer 1

There are 4 atoms to the unit cell so the mass of a unit cell is
4*atomic mass Cu/6.02E23 = ?
density = mass/volume
Substitute mass and density and solve for volume = ?
V^1/3 = edge length = a
4r = a*2^1/2
Solve for r. My periodic table says Cu is 1.28 angstroms.

Answer 2

127.3