Two ions `A^(o+)` and `B^(Θ)` have radii `88` and `200` pm, respectively. In the close-packed crystal of compound `AB`, predict coodination number of `A^(o+)`.

Explanation

`r_+/r_(-) =(r(A^+))/(r(B^-))="88pm"/"200pm"=0.44`
it lies in the range 0.414 to 0.732
Hence, the coordination number of `A^+`=6