NEET Chemistry The Solid State Questions Solved

Iron(II) oxide has a cubic structure and each unit cell has a size of 5$\stackrel{\circ }{A}$. If density of this oxide is 4 g cm-3, calculate the number of Fe2+ and O- ions present in each unit cell.

(Atomic mass of Fe = 56, O = 16, NA = 6.023$×$1023 and  1$\stackrel{\circ }{A}$ = 10-8 cm)