Which of the following statement are correct for the ionic solids in which positive and negative ions are held by strong electrostatic attractive forces ?

Options

A. The radius ratio `r^(+)//r^(-)` increases as co`-` ordination number increases
B. As the difference in size of ions increases co`-` ordination number increases
C. When `co-` ordination number is 8 , the `r^(+)//r^(-)` ratio lies between `0.225` to `0.414`
D. In ionic solid of the type `AX(ZnS,` Wurtzite `)` the co`-` ordination number of `Zn^(+)` and `S^(+)` are 4 and 4 respectively

Answer

a,b,d

Explanation

When `r^(+)/(r^(-))` ration lies between `0.225` to `0.414`, then co`-` ordination number is 4