what is polarising power?
Polarizing power can be defined as the ability of a cation to attract the electron cloud towards itself. Polarising power is proportional to charge/size.
If the size of the cation is small, it will have more charge density and hence its polarising power increases whereas in anions with increase in its size polarisability increases. Also, higher the charge on a cation more is its polarizing power while higher the charge of an anion more is its polarisability.