Calculating Density Bravais Lattices

1. The problem statement, all variables and given/known data

Calculate the density of Iron with the following information.

side length = 2.86 angstroms

Atomic weight = 55.85

Body centered cubic, so 2 atoms per unit cell.





2. Relevant equations

Density = ((# of atoms)(Atomic Weight)) / ((volume of cell)/Avogadro's Number))





3. The attempt at a solution

So this should be really easy, but I can't get the correct number with this formula, what am I doing wrong?



Atomic Weight of 55.85 means a mass of 9.274117017e-26 kg.

Side Length of 2.87 angstroms mean that the side length is 2.87E-10 Meters.

Cube this side length to get the total volume.



so using the formula...

(2)(9.274117E-26) / (2.87E-10)^3*(6.022^23) = 1.302915E-20 kg/m^3.. which is obviously very incorrect... Help meh?