Predict the structure of MgO. The radius of `Mg^(2+)` ion is 65 pm and radius of `O^2` ion is 140 pm Also find the co-ordination number

Explanation

The radius of `Mg^(2+)` ion =65 pm
The radius of `O^2` ion =140pm
The radius ratio = radius of cation/radius of anion `= ("radius of" Mg^(2+))/("radius of " O^2) =65/140=0.464`
Since, the radius ratio lies in the range of 0.414 - 0.732, therefore, co-ordination number is 6. Hence, the structure of MgO is octahedral