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Physics

Nuclear Force – Definition, Properties, and Role in Physics

Nuclear Force – Definition, Properties, and Role in Physics

Q: 3. What are 4 properties of nuclear force?

Four key properties of the strong nuclear force are: 1. Short range: It acts only over very short distances. 2. Strong attraction: It's significantly stronger than the electromagnetic force at nuclear distances. 3. Charge independence: The force between two protons is the same as between two neutrons or a proton and a neutron. 4. Saturation: A nucleon interacts strongly with only a limited number of other nucleons.

Properties and Types of Nuclear Force with Examples

The topic of nuclear force is important in physics and helps us understand the stability of atomic nuclei, the behavior of fundamental particles, and the source of the Sun’s energy. Mastering this concept is essential for students preparing for board exams, JEE, NEET, and understanding various nuclear reactions in science and technology.

Understanding Nuclear Force

Nuclear force refers to the extremely strong attractive force that acts between protons and neutrons (collectively called nucleons) inside the nucleus of an atom. It is a fundamental force of nature, responsible for binding the nucleus together against the electrostatic repulsion between protons. Nuclear force plays a vital role in topics like atomic nucleus, strong interaction, and binding energy.

Formula or Working Principle of Nuclear Force

The concept of nuclear force is often explained with reference to its strength and range, even though there is no simple universal formula like F = ma or Coulomb’s law. However, it can be approximately expressed as a function of distance (r) between nucleons:

F(r) ≈ -a · exp(−r/b) / r, where 'a' and 'b' are constants and r is measured in femtometers (fm, 10⁻¹⁵ m).

The force is maximum around 1 fm, becomes negligible beyond 2.5 fm, and is responsible for holding nucleons together.

Here’s a useful table to understand nuclear force better:

Nuclear Force Table

Concept	Description	Example
Nuclear Force	Attractive force binding protons and neutrons in the nucleus	Holds atomic nuclei together
Strong Nuclear Force	Strongest interaction, short range, binds nucleons directly	Fusion in the Sun
Weak Nuclear Force	Weaker, even shorter range, causes radioactive decay	Beta decay in Carbon-14

Worked Example / Practical Experiment

Let’s solve a problem to understand nuclear force:

1. **Identify Known Values:** Two protons are separated by 1.2 fm inside a nucleus.

2. **Apply Nuclear Force Concept:** The electrostatic repulsion (Coulomb force) wants to push them apart, but the nuclear force is much stronger at this distance.

3. **Solve and Analyze:** As the protons approach within 1–2.5 fm, nuclear force becomes dominant and keeps the nucleus stable.

Conclusion: This illustrates why atomic nuclei don’t fly apart, even though like charges repel each other, because of the strong nuclear force.

Practice Questions

Define nuclear force with an example.
What formula is used to describe nuclear force? Explain its range.
How does nuclear force overcome electrostatic repulsion inside an atomic nucleus?
Differentiate between strong nuclear force and weak nuclear force.

Common Mistakes to Avoid

Assuming nuclear force has an infinite range like gravity or electromagnetism—it is actually very short-range.
Thinking nuclear force only acts between protons— it acts between all nucleons (proton-proton, neutron-neutron, proton-neutron).
Confusing strong nuclear force (which binds nucleons) with the weak force (involved in beta decay), though both are called "nuclear forces."

Real-World Applications

Nuclear force is widely used in fields like nuclear energy generation, nuclear medicine, particle accelerators, and in studying cosmic events such as stellar fusion. It is fundamental to understanding nuclear fission in reactors and bombs, as well as the synthesis of elements in stars. Vedantu helps you connect such concepts with real-world physics applications and careers in science.

In this article, we explored nuclear force — its meaning, mathematical nature, types, practical relevance, and usage in physics. Keep exploring such core physics topics with Vedantu to improve your subject knowledge and exam performance.

To learn more, check these related topics:

FAQs on Nuclear Force – Definition, Properties, and Role in Physics

1. What is the definition of nuclear force?

Nuclear force is the strong attractive force that binds protons and neutrons together within an atom's nucleus, overcoming the electrostatic repulsion between positively charged protons. It's a short-range force, only significant at distances of about 1-2.5 femtometers.

2. What are the two types of nuclear forces?

The term "nuclear force" generally refers to the strong nuclear force, responsible for binding nucleons (protons and neutrons). However, there's also a weak nuclear force, which is involved in radioactive beta decay. The strong force is much stronger than the weak force.

3. What are 4 properties of nuclear force?

Four key properties of the strong nuclear force are: 1. Short range: It acts only over very short distances. 2. Strong attraction: It's significantly stronger than the electromagnetic force at nuclear distances. 3. Charge independence: The force between two protons is the same as between two neutrons or a proton and a neutron. 4. Saturation: A nucleon interacts strongly with only a limited number of other nucleons.

4. Why is nuclear force the strongest force?

While gravity is the dominant force at large scales, the strong nuclear force is the strongest of the four fundamental forces at the scale of the atomic nucleus. It overcomes the much weaker electromagnetic repulsion between protons, holding the nucleus together.

5. How is nuclear force different from electrostatic force?

Electrostatic force acts between charged particles, and it is a long-range force (decreasing with distance as 1/r²). The nuclear force is a much stronger, short-range force that acts specifically between nucleons and is independent of charge.

6. What is the formula for nuclear force?

There isn't a simple, single formula for nuclear force like there is for gravity or electromagnetism. Its complex nature requires quantum chromodynamics (QCD) for a complete description. However, various models and approximations are used to describe its effects in nuclear physics calculations.

7. What is the range of the nuclear force?

The nuclear force has an extremely short range, typically only about 1 to 2.5 femtometers (1 femtometer = 10^-15 meters). This is why it's only relevant at the scale of the atomic nucleus.

8. How does nuclear force influence nuclear fission and fusion?

Nuclear fission involves splitting a heavy nucleus into lighter ones, releasing energy because the strong nuclear force is weaker in the larger nucleus. Nuclear fusion combines lighter nuclei into a heavier one, also releasing energy because the binding energy per nucleon is higher in the heavier nucleus. Both processes involve the strong nuclear force.

9. Is nuclear force always attractive?

At the typical distances within a nucleus, the strong nuclear force is primarily attractive. However, at very short distances, a repulsive component becomes significant, preventing nucleons from collapsing into each other.

10. What are some examples of applications of nuclear force?

Applications of our understanding of nuclear force include: Nuclear power generation (fission), nuclear medicine (radioactive isotopes), and nuclear weapons. Furthermore, nuclear fusion powers stars and is being researched as a potential future energy source.

11. How does the strong nuclear force differ from the weak nuclear force?

The strong nuclear force is responsible for binding protons and neutrons together, while the weak nuclear force is responsible for certain types of radioactive decay, such as beta decay. The strong force is significantly stronger than the weak force and has a much shorter range.

12. Why don’t we feel nuclear force in daily life?

The extremely short range of the nuclear force limits its effects to the scale of atomic nuclei. The force is negligible at larger distances, unlike gravity and electromagnetism, which have much longer ranges and thus are felt on a macroscopic scale.