The fundamental particle which are responsible for leping nucless togather is

Options

A. Meson
B. Antiproton
C. Positron
D. Electron

Explanation

To solve the question regarding the fundamental particles responsible for holding the nucleus together, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Nucleus**: The nucleus of an atom is composed of protons and neutrons. These particles are collectively known as nucleons.

2. **Identifying the Fundamental Forces**: In particle physics, there are four fundamental forces: gravitational, electromagnetic, weak nuclear, and strong nuclear forces. The strong nuclear force is the one that holds the nucleus together.

3. **Role of Quarks**: Protons and neutrons are not elementary particles; they are made up of smaller particles called quarks. Quarks are held together by the strong force.

4. **Force-Carrying Particles**: The strong nuclear force is mediated by particles known as gluons. Gluons are the exchange particles that carry the strong force between quarks.

5. **Understanding Mesons**: In addition to gluons, mesons (which are made up of a quark and an antiquark) also play a role in the interactions between nucleons. They can be thought of as carriers of the strong force between protons and neutrons.

6. **Conclusion**: The fundamental particles responsible for keeping the nucleus together are mesons, as they mediate the strong force between the nucleons.

### Final Answer:
The fundamental particle responsible for keeping the nucleus together is **mesons**.

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