Question

In which of the following crystals of ionic compounds would you expect maximum distance between the centres of cations and anions?

• A. LiF
• B. CsF
• C. CsI
• D. LiI

Answer 1

The correct option is C CsI

Ionic radii is the distance between the nucleus of an ion and a point up to which the nucleus has its influence on its electron cloud.

The size of ions increases on moving from top to bottom in a group.

Hence, the maximum distance between the centres of cations and anions is in CsI because Cs is the largest cation and I is the largest anion.

Hence, the correct option is C.