During a negative beta decay,

Options

A. an atomic electron is ejected
B. an electron which is already present with in the nucleus is ejected
C. a neutron in the nucleus decays emitting on electron
D. a part of the binding energy is converted into electron

Explanation

**Step-by-Step Solution:**

1. **Understanding Negative Beta Decay**: In negative beta decay, a neutron in the nucleus of an atom decays into a proton. This process involves the emission of a beta particle, which is an electron, and an antineutrino.

2. **Identifying the Components of the Decay**: The decay can be summarized by the equation:
\[ n \rightarrow p + e^- + \bar{\nu} \]
where \( n \) is the neutron, \( p \) is the proton, \( e^- \) is the emitted electron (beta particle), and \( \bar{\nu} \) is the antineutrino.

3. **Analyzing the Options**:
- **Option A**: "An atomic electron is ejected." This is incorrect because the electron emitted during negative beta decay is not an atomic electron; it is produced from the decay of the neutron.
- **Option B**: "An electron which is already present within the nucleus is ejected." This is also incorrect as there are no electrons present in the nucleus that can be ejected.
- **Option C**: "A neutron in the nucleus decays emitting an electron." This is correct as it accurately describes the process of negative beta decay.
- **Option D**: "A part of binding energy is converted into electrons." This statement is misleading as the electron is not created from binding energy but is a product of the decay process.

4. **Conclusion**: The correct answer is Option C, as it accurately describes the process of negative beta decay where a neutron decays into a proton and emits an electron and an antineutrino.

**Final Answer**: Option C is correct.

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