Question

explain fazans rule/////?????

Answer 1

Fazan's Rule
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→ covalent bonding is favoured by those factors that favour polarisation.

→ polarisation is the increase in the covalent character of an ionic bond due to the attraction between loosely electrons of larger anions by the smaller cation.

the following rule are followed for deciding polarisation and hence covalent character :-

(a) the change on cation or anoins must be larger .

(b) the cation must be smaller

(c) the anions must be larger

(d) the polarising power of those cations which don't have inert gas configuration will more in comparison to cation having inert gas configuration .
example :-
polarising power of Cu+ ion is more in comparison to the polarising power of Na+ .

Answer 2

Explanation:

Fajans rule explains polarising power : CATION. It says that as the charge density on metal cation increase it forms ionic compound with large covalent character . polarising power of cation depends on charge density of cation. i.e., smaller the size and greater the charge, more will be polarising power.