FUNDAMENTAL FORCES/INTERACTIONS

FUNDAMENTAL FORCES/INTERACTIONS: There are only four types of forces/interactions in the nature. All the other forces can be expressed in terms of these forces. These forces are called fundamental forces. These forces together account all the phenomena microscopic as well as macroscopic occurring in the universe. These forces are as follows:

1.       Strong force: This force acts between hadrons/quarks. It is always attractive and strongest force in nature. It is mediated by mesons/gluons. This force is charge and mass independent and saturative. Its range is very small about (~10^-15m). It is responsible for the stability of nucleus.

2.       Electromagnetic force: the force which acts in between all charged particles is called an electromagnetic force. It is infinite range force. It is stronger than gravitational but 10^2 times weaker than strong force. It is independent with mass, color, etc. It is attractive (for unlike charge) and repulsive (for like charge). It is mediated by photons. It is responsible for the stability of atoms, binding atoms in matter and chemical reactions.

3.       Gravitational force: This force acts between the particles having mass. It is always attractive. Its range is infinite. It is inverse square force and is independent with color, charge etc. It is weakest force of nature (10^39 times weaker than strong force). It is mediated by gravitation. It is responsible for the stability of universe.

4.       Weak force: this force acts between leptons and hadrons. It has shortest range (~10^-17m). it is stronger than gravitational force but weaker than electromagnetic and strong force (10^13 times weaker than strong force). Mediators of this force are intermediate bosons (w+-), z^0. This force is responsible for β decay.