Hey, do you want to learn about the Properties of nuclear force? If yes. Then keep reading.
What are Nuclear forces?
The strong forces of attraction which firmly hold the nucleons in the small nucleus and account for the stability of the nucleus are called nuclear forces.
Properties of Nuclear Forces
The nuclear force is a short-range force.
- They are appreciable when the distance between nucleons is of the order of $2.2 \times 10^{-15} \mathrm{~m}$
- They become negligible when the distance between nucleons is greater than $4.2 \times 10^{-15} \mathrm{~m}$
- When the distance between two nucleons is less than $1 \times 10^{-15}$ m the nuclear forces become strongly repulsive
Nuclear forces are the strongest force in nature
Nuclear forces are charge independent
The force between a pair of protons, a pair of neutrons, and a pair of neutrons and protons are equal.
$F(n-n)=F(p-p)=F(n-p)$
The net force between pair of neutrons and a pair of neutron and proton is equal. This is slightly greater than the force between pair of protons because force between protons is reduced due to electrostatic repulsion
Net force F (n — n) = Net force F(n — p) > Net force F (p — p)
Nuclear forces are spin dependent
- The nuclear force depends on the relative orientation of spins between two interacting nucleons
- The force of attraction between two nucleons with parallel spin is greater than the force between nucleons with antiparallel spin.
- Deutron is formed in a bound state only if spins of neutron and proton are parallel.
Nuclear forces show saturation property
- The nucleon in the nucleus interacts with its nearest neighbor only.
- It remains unaffected by the presence of other surrounding nucleons.
- The nuclear force between a pair of nucleons in light and a heavy nucleus is equal.
Nuclear forces are non-central forces
- They do not act along line joining the center of two nucleons
- The non-central component depends on the orientation of spins relative to the line joining the center of two nucleons.
Nuclear forces are exchange forces
- The nuclear forces originate by exchange of mesons $\left(\pi^{+}, \pi^{\circ}, \pi^{-}\right)$ between the nucleons
- mass of meson = 0.15 amu = 140 MeV = 280 × mass of electron
- $p-p$ force $\mathrm{p}+\pi^{\circ} \longleftrightarrow \mathrm{p}$
n – n force $\mathrm{n}+\pi^{\circ} \longleftrightarrow \mathrm{n}$
n – p force $\mathrm{p}+\pi^{-} \longleftrightarrow \mathrm{n}$
$\mathrm{n}+\pi^{+} \longleftrightarrow \mathrm{p}$ - The theory of exchange forces was given by Yukawa
- The potential energy of a particle in this force field is given by Yukawa potential $U(r)=U_{0} e^{-r / r_{0}}$ where
$\mathrm{r}_{0}$ & $\mathrm{U}_{0}$ are constants.
so, that's all from this article. I hope you get the idea about the Properties of nuclear force. If you found this article informative then please share it with your friends. If you have any confusion related to this topic then feel free to ask in the comments section down below.
For a better understanding of this chapter, please check the detailed notes of Nuclei Physics. To watch Free Learning Videos on physics by Saransh Gupta sir Install the eSaral App.