Assertion `(A) :` Nucleus of the atom does not contain electrons, yet it emits `beta-`particles in the form of electrons.
Reason `(R):` In the nucleus , protons and neutrons exchange mesons frequently.

Options

A. If both `(A)` and `(R)` are correct , and `(R)` is the correct explanation of `(A)`
B. If both `(A)` and `(R)` are correct, but (R) is not the correct explanation of `(A)`
C. If `(A)` is correct, but `(R)` is incorrect.
D. If `(A)` is incorrect, but `(R)` is correct.

Explanation

To analyze the assertion and reason provided in the question, let's break it down step by step.

### Step 1: Understanding the Assertion
The assertion states that the nucleus of the atom does not contain electrons, yet it emits beta particles in the form of electrons.

- **Explanation**: The nucleus is made up of protons and neutrons (collectively called nucleons). Electrons are not found in the nucleus; instead, they orbit around the nucleus in electron shells. However, during a process called beta decay, a neutron in the nucleus can transform into a proton and emit a beta particle, which is an electron.

### Step 2: Understanding the Reason
The reason states that in the nucleus, protons and neutrons exchange mesons frequently.

- **Explanation**: This statement refers to the strong nuclear force that holds the nucleus together. While it is true that protons and neutrons interact via the exchange of particles called mesons, this is not the mechanism that leads to the emission of beta particles. In beta decay, it is the conversion of a neutron into a proton that results in the emission of an electron, not the exchange of mesons.

### Step 3: Evaluating the Assertion and Reason
Now we need to evaluate the correctness of both statements:

- **Assertion (A)**: Correct. The nucleus does not contain electrons, and it can emit beta particles in the form of electrons during beta decay.
- **Reason (R)**: Incorrect. The reason provided does not accurately describe the process of beta decay. Beta decay involves the transformation of a neutron into a proton, not the exchange of mesons.

### Conclusion
Based on the analysis:
- The assertion is true.
- The reason is false.

Thus, the correct answer is that the assertion is correct, but the reason is incorrect.

### Final Answer
**Option C**: Assertion is correct. Reason is wrong.

---