Question

Describe how contact force like friction etc as well as chemical reaction are instances of electromagnetic force

Answer 1

We know that atoms and molecules of matter consists of elementary charged constituents like electrons and protons. Since two fundamental forces- 'strong nuclear force and weak nuclear force', operate only at nuclear scales so that these forces can not be responsible at the atomic and molecular level. Now we consider other two fundamental forces- 'the electromagnetic force and the gravitational force'. The electromagnetic force is so much stronger than the gravitational force so that it dominates in all phenomena at atomic and molecular scales. Thus we can conclude that it is mainly the electromagnetic force that governs the structure of atoms and molecules, the dynamics of chemical reactions and the mechanical, thermal and other properties of materials. The electromagnetic force is responsible for the macroscopic forces like tension, friction, normal force, spring force etc.