Given: Radius of cation Na+ (r+ ) =150 pm
To find: Radius of anion Cl– (r– ) =?
Formula:
Radius ratio = Radius of the cation/ Radius of the anion
Calculation: NaCl has octahedral structural arrangement
The range of r+/r- for stable six fold coordination is 0.414 to 0.732
Hence the radius of cation can be calculated by