Nucleus-Nuclear Forces

Introduction

As we know that atoms are made up of electrons, neutrons, and protons, the centre of the atom consists of a nucleus made up of protons and neutrons, while electrons revolve around the nucleus. The nucleus is held together through nuclear forces.

Nuclear forces are powerful forces, forming bonds in the nucleus that are very hard to break. But when these bonds are broken, a large amount of energy is produced, and that process is called nuclear fission. Nuclear forces are almost 10 million times stronger than chemical binding. That is why it is used to produce electricity instead of any other chemical fuel like coal or petroleum since nuclear fission creates millions of times more energy per kilogram of fuel.

Nuclear Forces

The prominent problem scientists couldn’t wrap their heads around was that if the nucleus were made up of protons and neutrons, the protons would push each other away because they all have a positive electromagnetic charge which would disintegrate the atom. So how did the nucleus keep itself integrated even though the electromagnetic force present does the opposite? The solution to this question led to the discovery of nuclear forces. 

What are Nuclear Forces?

Nuclear forces keep holding the integrity of our universe as we know because if there were no nuclear force, then everything would disintegrate on an atomic level; this is because they hold the nucleus of an atom together.

They have a very short range of 1 femtometer, but nuclear forces are powerful; they act against the electromagnetic forces of the protons to keep the nucleus intact and are almost 10 million times stronger than chemical binding forces. When these bonds are broken, they release an enormous amount of energy. This is mainly used for the production of electricity. 

Discovery

Chadwick discovered the neutron in 1932, but he could not figure out how the nucleus was bound together. Electromagnetic forces were struck out because the repulsive electrical force of protons would disintegrate the nucleus. But in 1935, a Japanese physicist named Hideki Yukawa proposed his theory about a new force according to which massive bosons interacted with two nucleons, which could be the reasons for nuclear forces. This concept is no longer considered fundamental but represents the best working model for a quantitative NN potential.

Types of nuclear forces

There are classified into two types 

• Strong nuclear forces 
• Weak nuclear forces

Strong nuclear forces

Strong nuclear forces are the strongest of all fundamental forces, around 130 times stronger than electromagnetic forces. These forces work on a very small scale. Strong nuclear forces work around one femtometer that is 1 x 10-15 m.

Once we get to the level of a nucleus, we can observe that all the components of the nucleus are bonded together by strong nuclear forces. 

When two protons are at a distance of more than two femtometers, they repulse each other due to electromagnetic forces. But if the protons are at a distance of fewer than two femtometers, they are attracted to each other by strong nuclear force, and the electromagnetic force is negated.

But when atoms with a large nucleus like uranium whose diameter is larger than or near the range of strong nuclear force, they are pushed away from each other by the electromagnetic force, which causes radiation. 

Weak nuclear forces

Weak nuclear force or weak interaction is one of nature’s fundamental forces responsible for the decay of unstable subatomic particles such as mesons. Weak nuclear initiates the process of nuclear fusion. These forces start the nuclear fusion that keeps the Sun burning.

Conclusion

In this study material, we have learned that nuclear forces bind the nucleus of an atom together. Nuclear forces have a very short range of 1 femtometer. There are two types of nuclear forces: strong and weak.

Strong nuclear forces are around 130 times stronger than electromagnetic forces. That is why they can hold the protons present in the nucleus together by opposing the repulsive force in the positively charged protons. But when the nucleus of an atom is too large for the range of strong nuclear force, then electromagnetic repulsion between the protons exceeds the strong nuclear force, and protons start escaping the nucleus, which results in decay or radiation.

Weak nuclear forces are responsible for the decay of subatomic particles like mesons which then initiates nuclear fusion. Nuclear fusion, started by weak nuclear forces, fuels the sun.