Question

solid AB has ZnS type struture. if the radius of A⁺ is 22.5 pm then what will be the radius of B^- ?

Answer 1

Radius ratio = r⁺/r^- = A⁺/B-
A⁺ = r⁺= radius of cation = 22.5 pm
B^- = r^- = radius of anion = ?

Note-
AB has ZnS type of structure i.e AB has tetrahedral holes. Therefore,

Radius ratio
= r⁺/r^- = A⁺/B^- = 0.225
=> B^- = A⁺ / 0.225 = 22.5 pm/0.225 = 100 pm