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^(-)))= (88"pm")/(200"pm") = 0.44`
It lies in the range 0.414 to 0.732
Hence, the cordination number of ` A^(+) = 6`