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What is screening effect ? |
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Answer» Solution :The repulsive FORCE between INNER shell electrons and the valence electrons leads to a decreases in theelectrostatic attractive forces acting on the valence electrons ACTS as a shield between the nucleus and the valence electrons Pauling 's scale : (i) Electronegativity is the relative tendency of an element present in a covalently bonded molecule to attract the shared pair of electrons towards itself. (ii)Pauling assigned arbitrary value of electro negativities for hydrogen and fluorine as 2.2 and 4 respectively . (iii)Based on this the electro negativity values for other ELEMENTS can be calculated using the following expression . `(X_(A)-X_(B))=0.182sqrt(E_(AB)-(E_(A A)xxE_(BB))^(1//2))` Where`E_(AB),E_(aa)andE_(bb)`are the bond dissociation energies of `AB,A_(2)andB_(2)` molecule respectively`X_(A)andX_(B)`are elctro negativity values of A and B. |
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