What Is Nuclear Force And Its Properties
The force that acts between nucleons, such as protons and neutrons, to create atomic nuclei is called “nuclear force.” Because the nuclear force is much stronger than the electromagnetic force within an atomic nucleus, it is also called the “strong force.” The atomic nucleus is a “mass” of protons and neutrons bound together by a “strong force.”
According to Hideki Yukawa’s meson theory, the “strong force” is generated by the exchange of pions between nucleons. It looks as if the nucleons are playing catch with each other with the pions. However, it is surprisingly difficult to describe this situation mathematically.
Pions have mass, so they cannot move at the speed of light. As a result, there is a limit to the distance between nucleons that can exchange pions. When nucleons are separated to a certain extent, it is not possible to reach the other nucleon using only the possible existence time of pions, which is determined by the uncertainty principle of quantum mechanics.
Therefore, “strong force” can only act over a short distance, about the size of an atomic nucleus, and does not appear on a daily scale. I would like to emphasize that “strong force” is not only a much stronger force than electromagnetic force, but also has the property of acting only over a short distance.
As the atomic number increases, the number of protons and neutrons inside the nucleus increases, so the radius of the nucleus increases. As the nucleus becomes larger, the distance between the nucleons also increases, and the effect of the “strong force” rapidly weakens. At this time, the electromagnetic force acting between the protons appears as a repulsive force, and the nucleus becomes unstable.
Furthermore, even if the atomic number is small, it is possible for an atomic nucleus to be unstable due to an imbalance of protons and neutrons.
Unstable nuclei tend to release energy and transform into stable nuclei. This property is radioactivity, and when it occurs, it releases a huge amount of energy. This energy comes from the “strong force” that binds the atomic nuclei together.
Nuclear force, also known as the strong nuclear force or strong interaction, is one of the fundamental forces in nature that acts between particles called nucleons, which are protons and neutrons found in the nucleus of an atom. Here are some key properties and characteristics of nuclear force:
- Strongest Force at Short Distances: Nuclear force is the strongest of the four fundamental forces (gravity, electromagnetism, weak nuclear force, and strong nuclear force) at extremely short distances, typically within the range of the size of atomic nuclei (about 10^(-15) meters).
- Short-Range Force: Unlike gravity and electromagnetism, which have infinite range, nuclear force is a short-range force that acts only within the nucleus of an atom. It becomes negligible at distances greater than the size of the nucleus.
- Attraction Between Nucleons: Nuclear force is an attractive force that binds nucleons together within the nucleus. It overcomes the electrostatic repulsion between positively charged protons and holds the nucleus together despite the electromagnetic repulsion between protons.
- Charge Independence: Nuclear force is charge-independent, meaning it does not depend on the electric charge of the nucleons involved. It acts equally between protons and neutrons and is not affected by the presence of electric charges.
- Spin Dependence: Nuclear force is spin-dependent, meaning it depends on the intrinsic spin of the nucleons involved. Nucleons with parallel spins (spin-up or spin-down) experience a stronger nuclear force compared to those with antiparallel spins.
- Saturation Property: Nuclear force exhibits a saturation property, which means that it remains approximately constant within the nucleus regardless of the number of nucleons. This property contributes to the stability of atomic nuclei.
- Residual Interaction: Nuclear force includes a residual or residual interaction component, which is responsible for the binding energy of nucleons in the nucleus beyond what is accounted for by the strong force alone.
- Meson Exchange: The mechanism behind nuclear force involves the exchange of particles called mesons, specifically pions (π mesons), between nucleons. Meson exchange theory describes how the exchange of virtual mesons mediates the attractive force between nucleons.
- Fundamental Force in Nuclear Physics: Nuclear force is crucial for understanding the structure and stability of atomic nuclei, nuclear reactions, and the behavior of matter at nuclear scales. It plays a central role in nuclear physics and nuclear engineering.
Overall, nuclear force is a fundamental force that binds nucleons together within atomic nuclei, giving rise to the stability of matter and the existence of elements in the universe. It is essential for understanding the structure and behavior of atomic nuclei and plays a key role in nuclear physics research and applications.