Which of the following pairs particles cannot exert nuclear force on each other ?

Options

A. proton and electron
B. Neutron and electron
C. Electron and neutron
D. All of these

Answer

To solve the question "Which of the following pairs of particles cannot exert nuclear force on each other?", we will analyze the nature of nuclear forces and the types of particles involved.

### Step-by-Step Solution:

1. **Understanding Nuclear Force**:
- Nuclear force is a strong interaction that occurs between nucleons (protons and neutrons) within an atomic nucleus. It is responsible for holding the nucleus together.

2. **Identifying the Particles**:
- The particles that can exert nuclear force are protons and neutrons. These are collectively known as nucleons.
- Electrons, on the other hand, are not part of the nucleus and do not participate in nuclear forces.

3. **Analyzing the Pairs**:
- **Proton and Proton**: They can exert nuclear force on each other.
- **Neutron and Neutron**: They can exert nuclear force on each other.
- **Proton and Neutron**: They can exert nuclear force on each other.
- **Proton and Electron**: They cannot exert nuclear force on each other; they interact through electromagnetic force.
- **Neutron and Electron**: They also cannot exert nuclear force on each other; they interact through weak nuclear force and electromagnetic force.

4. **Conclusion**:
- The pairs that cannot exert nuclear force are:
- Proton and Electron
- Neutron and Electron
- Therefore, the correct answer is that all the options listed (if they include these pairs) cannot exert nuclear force on each other.

### Final Answer:
The pairs of particles that cannot exert nuclear force on each other are:
- Proton and Electron
- Neutron and Electron

Thus, if the options include these pairs, the correct answer would be "All of these".