Caesium chloride may be considered to form interpenetrating simple primitive cubic crystals.The edge length of unit cell is 412pm.Determine the ionic radius of $Cs^+$ if the ionic radius of $Cl^-$ is 181pm.Given :M(Cs)=$133gmol^{-1}$

Question

$\begin{array}{1 1}175.8pm\\185.8pm\\165.8pm\\125.8pm\end{array} $