What are nuclear forces ? State theirfour properties.Explain the possible cause of these forces.

Explanation

Nuclear forces : The forces holding the nucleons together inside the nucleus are called nuclear forces.
Properties of nuclear forces :
1. These forces are the strongest forces in nature.
2. These forces are short range forces. These forces become negligible when distance between the nucleons is more than 4-2 fermi.
3. There are basically very strong attractive forces, but contain a small component of repulsive forces.
4. Nuclear forces are saturated forces, i.e., a nucleon experiences force only due to the neighbouringnucleons.
5. These forces are charge independent. 3
6. These forces are spin dependent.
7. These forces are exchange forces.
8. These forces are non-centrol forces. Origin of the nuclear forces :
According to Yukawa, the nuclear forces arise due to continuous exchange of particles known as mesons between the nucleons. These particles have a mass 270 times the mass of an electron. These are three types of measons :
(i) Mesons carrying no charge called neutral pi meson `(pi^(@))`.
(ii) Mesons carrying unit +ve charge each were called positive pi meson `(pi^(-))`.
(iii) Mesons carrying unit -ve charge each were called negative pi meson. The forces between a pair of neutrons or a pair of protons are the results of the exchange of neutral meson `(pi^(@))` between them i.e.
In the above cases, a proton or a neutron is converted into a new state after emitting or absorbing the `pi^(@)` meson. The exchange of tt meson keeps the nucleons bound.together which is responsible for nuclear forces.