Mesomeric Effect

Mesomeric effect is the process of electron density redistribution i.e. addition or removal of electron density, occuring, through a pi-orbital through conjugated systems.

Inductive effect

When electron density in a molecule is shifted, as a result of the polarization of a bond by a nearby electropositive or electronegative atom then it is known as inductive effect.

Steric effect

Steric effect is the change in the reactivity and preferred shape of the molecule as a result of the overlapping of electron clouds in a molecule, when atoms are brought closer together.

Hyperconjugation

It is a weak form of conjugation resulted from the ineraction of electrons in a sigma-bond with neighbouring empty pie-orbital or p-orbital resulting in an increased stability of the system.