Question

The polarisability of the halide ions in the salts CaX2 is in the order of

Answer 1

As the size of the halogen ions increases, larger will be its ionic radius and greater will be its charge (increase in deformability of its electron cloud or its softness) and more polarisable will be the halide ion. Hence as the size of the halogens increases down the group, polarisability of the halogens increases down the group. The increasing polarisability order of the halide ions is:

A) F- < Cl- < Br-, I-