Question

How does electronegativity affect a chemical bond?

Answer 1

Electronegativity of an element is the tendency of an atom to attract the shared pair of electrons towards itself. Even though it is qualitative, it helps in the prediction of the type of bond which exists between two bonded atoms.

Complete step-by-step answer:
We know that Electronegativity is the tendency to attract the shared pair of electrons towards itself. It helps to decide the type of chemical bond which will be formed between two atoms combined with each other.

We should remember that in any chemical bond formed, it is the relative electronegativity difference between the combining atoms or elements which helps in predicting the type of bond. As a general rule, the following facts show how electronegativity affects the chemical bond.
1. If the difference between the electronegativity of two elements in a bond is above , then the compound formed will be an ionic compound. The type of bond in such compounds is called ionic bond. For example, Sodium chloride is an ionic compound
2. If the difference between the electronegativity of two elements in a bond is less than , then the compound formed will be a covalent compound and the bond formed will be a covalent bond. For example, methane, hydrogen chloride.

In a covalent compound also, there are two types of bonds possible which are polar covalent bond and nonpolar covalent bond, which will depend on the electronegativity of the atom of the compound.
Non-Polar Covalent Bond: if the covalent bond is formed between the two similar atoms, having similar electronegativity such bonds are called polar covalent bonds. In such compounds the shared pair of electrons is equally attracted by all atoms. For example, Oxygen.

Polar compound: if in a covalent bond one atom is highly electronegative, then that atom will attract the electron toward itself and as a result opposite partial charges develop in the compound. In such compounds the shared pair of electrons is more shifted towards the electronegative element. Example: HCl

Note: On Pauling’s scale the electronegativity of chlorine is more than that of nitrogen but practically we know that electronegativity of nitrogen is greater than chlorine and we should always remember this fact while dealing with the questions involving electronegativity concept.