If the radius of Mg2+ ion, Cs+ ion, O2- ion, S2- ion and Cl- ion are 0.65 Å , 1.69 Å, 1.40 Å, 1.84 Å, and 1.81 Å respectively. Then the co-ordination numbers of the cations in the crystals of MgS, MgO and CsCl respectively are:
Calculate the ionic radius of a Cs+ ion assuming the cell edge length for CsCl is 0.4123 nm and that the ionic radius of a Cl- ion is 0.181 nm.