Question

How is raduis ratio rule is it useful in predicting structure of ionic solids

Answer 1

radius ratio is the ratio of atomic radius of cation to anion in a compound  

                          geometry          coordination no

0.0155-0.0255  planar                3

0.0255-0.0314 tetrahedral            4

0.0314-0.0732 octahedral            6

>0.0732            cubic                   8