Given: Radius of Cation A+ (r+ ) = 58 pm
Radius of anion B– (r– ) = 210 pm
To find: The coordination number of AB = ?
Formula:
Radius ratio= Radius of the cation/Radius of the anion
Calculation:
From formula,
Radius ratio
Since the radius ratio lies in between 0.225 – 0.414
The coordination number of AB is 4
And the structure of AB is Tetrahedral