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fajan's rule

fajan's rule

by ankit dhingra -
Number of replies: 3
FAJAN RULE SAYS THAT DISTORTION OF ELECTRON CLOUD TAKES PLACE WHEN SIZE OF THE CATION IS SMALLER THAN ANION . WHAT IF ITS REVERSE THAT IS SIZE OF ANION IS SMALLER THAN CATION FOR EXAMPLE CESIUM FLUORIDE. HOW DO WE EXPLAIN ITS IONIC NATURE THOUGH HERE ALSO THERE SHOULD BE DISTORTION.
In reply to ankit dhingra

Re: fajan's rule

by gaurav sharma -

according to fajan's rule for ionic nature large cation and small anion is required since in cesium flouride

Cation = large

Anion  =  small

hence ionic .

In reply to gaurav sharma

Re: fajan's rule

by ankit dhingra -
dear friend gaurav all the books say that for applying fajans rule the size of cation should be  smaller than the anion and i have seen that size of cesium ion is greater than that of fluoride ion.
In reply to ankit dhingra

Re: fajan's rule

by gaurav sharma -

 According to fajan's rule condition for ionicity of a bond is

large cation small anion

reason: A  cation is formed by loosing an electron as we go lower down the group size inc and I.E decreases and anion is formed by gaining an electron

E.A decreases as we go down a group so small size = high E.A

also small cation polarizes to greater extent as compared to large  cation

.

TRY AND UNDERSTAND  THIS IF STILL NOT SATISFIED ............