Assertion :Radioactive nuclei emit `beta^-1` particles.
Reason :Electrons exist inside the nucleus.

Options

A. If the both assertion and reason are true and the reason is the correct explanation of the assertion
B. If both assertion and reason are true and the reason is not the correct explanation of the assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false statements.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states that "Radioactive nuclei emit β^- particles."

- **Explanation**: Radioactive decay can occur in several forms, including alpha decay, beta decay, and gamma decay. In beta minus (β^-) decay, a neutron in the nucleus of a radioactive atom decays into a proton, an electron (the β^- particle), and an antineutrino. The emitted electron is what we refer to as the beta minus particle. Therefore, this assertion is **true**.

### Step 2: Analyze the Reason
The reason states that "Electrons exist inside the nucleus."

- **Explanation**: In the context of beta decay, the electron that is emitted does not exist inside the nucleus prior to the decay. Instead, during beta minus decay, a neutron is transformed into a proton, and an electron (the β^- particle) is produced as a result of this transformation. The electron is not a pre-existing particle within the nucleus; rather, it is generated during the decay process. Therefore, this reason is **false**.

### Step 3: Conclusion
Based on the analysis:
- The assertion is **true**.
- The reason is **false**.

Thus, the correct answer is that the assertion is true, but the reason is false.