Sodium has a crystal structure (right) which can be thought of as a repetition of a unit cell shown on the left. The different colors just represent different relative positions in the unit cell.
[Figure: Shows crystal structure diagrams]
Given that sodium's unit cell is a cube with edge a = 0.428 nm and its atomic weight is 23 g/mol, what is the density of sodium?
a) 0.47 g/cm³
b) 0.94 g/cm³
c) 1.41 g/cm³
d) 4.23 g/cm³