Question

Distinguish between mesomeric effect and electromeric effect

Answer 1

if functional group is electron withdrawing group the positive charge in benzene is in congugation with pi system.. this effect is known as +ve mesomeric effect. Usually we refer to them as the same but the difference between the two is, Mesomeric effect is not applicable for single bond system.

Answer 2

Kondo effect of the adatom with the STM tip . ... second and also most important difference is that the phase boundary is