what is inert pair effect why it is shown by heavy elements explain

Dear amit

inert pair effect is nothing put the inability of s electrons to participate in the reaction.
s electrons are not able to participate bcoz of strong hold of nucleus (high penetration effect) or por shielding effect of electrons
therefore
+3 state stability will be in the order
Bi>Sb>As
and vice-versa for +5 stability
more big the atom more poor the shielding effect...

bigger atom have poor shielding effect cz
as the d or f electrons are situated very far frm each other
they give the nucleus to strengthen their hold on the s-electrons
and as s electrons show high penetrating effect ie they prefer to live near the nucleus
the hold of nucleus on 6s electrons is considerable...

nw as Pb+4 is unstable as its s-electrons have been taken it will easily take em(remember inert pair effect is most effective on the bottom most elemenst........hence it wrks on Pb also hence Pb doesn't wants it s-electrons to participate and hence its +2 oxidation is more stable than +4.....

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Badiuddin

the reductance of ns2 electrons to unpair and participate in bond formation called as inert pair effect .