in an ionic bond the cation tends to polarise the electron cloud of the anion by pulling electron density towards itself This causes development of covalent character in the ionic bond because the electron density gets localised in between the nuclei The tendency of the cation to bring about the polarisation of the anion is expressed as its polasising power The ability of ion to undergo polarisation is called its polarisability The polarising power of a cation or an anion is decided on the basis of `F` ajans' rules as follows .
(i) The smaller the cation, the higher is its polarising power
(ii) Cations with pseudo-noble gas configuration `(ns^(2)np^(6)nd^(10))` have relatively high polarising power than those with noble gas configuration `(ns^(2) np^(6))`
(iii) The larger the size of the anion, the higher is its polarisability
The ionic conductance of which of the following is the highest ? .

Options

A. `Li_((aq))^(o+)`
B. `Na_((ag))^(o+)`
C. `K_((aq))^(o+)`
D. `Cs_((aq))^(o+)`

Answer

D

Explanation

Charge density of `Cs _(aq)^(o+)` is the lowest in group 1 ions so it is less hydrated Hecne ionic conductance of `Cs_(aq)^(o+)` is the highest .