Question

I want understand about the weak nuclear and strong nuclear force that was stated in this chapters video

Answer 1

Nuclear Force Definition

Nuclear Force is defined as the force exerted between numbers of nucleons. This force is attractive in nature which binds protons and neutrons in the nucleus together. Since the protons are of same positive charge they exert a repulsive force among them. This can result in bursting of the nucleus. Hence to hold them together nuclear force is responsible.


Because of this attractive Nuclear Force, the total mass of the nucleus is less than the summation of masses of nucleons that is protons and neutrons. This force is highly attractive between nucleons at a distance of 10^–15 m or 1 femtometer (fm) approximately from their centers.

Nuclear forces are of two types namely,

1. Strong Nuclear Force
2. Weak Nuclear Force.

Nuclear forces are independent of the charge of protons and neutrons. This property of nuclear force is called charge independence. It depends on the spins of the nucleons that is whether they are parallel or no and also on the non central or tensor component of nucleons.

Strong nuclear force is about 100 times stronger than electromagnetism. These forces is also known as strong interactions.

Strong nuclear forces can be applied in two aspects: One is on Larger Scale and
other on Lower Scale.

1. On larger scale of about 1 to 3 fm distance, it is the force that binds the nucleons together to form nuclei.
2. On smaller scale of abut less than 0.8 fm distance, it is the force that binds quarks together to form nucleons that is protons and neutrons and also other particles like hadrons.

Strong Nuclear Force Examples
Strong nuclear forces help in holding sub atomic particles of protons together and also the nucleons together at larger scale.

1. Strong nuclear force leads to release of energy when heat is generated in Nuclear Power Plant to generate steam for generating electricity.
2. Energy is released when a Nuclear Weapon detonates which is due to strong nuclear forces.

Weak Nuclear Force
Weak Nuclear Force is one of the four fundamental force. Electromagnetic force, gravitational force and strong nuclear force are the other forces.

Weak Nuclear Force is caused by the emission or exchange of W and Z bosons. Weak nuclear forces are very short range because of the heaviness of the W and Z particles. Weak nuclear force results in the change of one type of quark to another type. This is also known as change of flavor / flavor change of quarks.

Weak Nuclear Force can transform a neutron into proton or proton into neutron. Weak nuclear forces act between quarks and leptons both. Weak interaction is responsible for the flavor change of quarks and leptons. The significance of weak nuclear force in flavor change of quarks makes it the interaction indulged in many decay phenomenons of nuclear particles which need a change of quark from one type to another.