TeX source:

n=\frac{1\: e^{-}}{atom}\times \frac{6.02\times 10^{23}\: atoms}{mol}\times \frac{1\: mol}{63.54\: g}\times \frac{1000\: g}{kg}\times \frac{8.80\times 10^{3}kg}{1\: m^{3}}