Iron oxide \( \mathrm{FeO} \), crystallises in a cubic lattice with a unit cell edge length of \( 5.0 Å\). If density of the \( \mathrm{FeO} \) in the crystal is \( 4.0 \, \mathrm{g\,cm^{-3}} \), then the number of \( \mathrm{FeO} \) units present per unit cell is ________ (Nearest integer) (Given: Molar mass of Fe and O is \( 56 \) and \( 16 \, \mathrm{g\,mol^{-1}} \) respectively)
