The emission of beta particle is from A)The valence shell of an atom B)The inner shell of an atom C)The nucleus due to the nuclear conversion `:`
Proton `rarr` neutron`+` electron D)The nucleus due to the nuclear conversion `:`
neutron `rarr` proton `+ ` electron

Options

A. innermost electron orbit
B. a stable nucleus
C. outermost electrons orbit
D. radioactive nucleus

Explanation

To solve the question regarding the emission of a beta particle, we need to understand the process of beta decay and analyze the provided options accordingly.

### Step-by-Step Solution:

1. **Understanding Beta Decay**:
- Beta decay is a nuclear process where a beta particle (which is a fast-moving electron) is emitted from the nucleus of an atom. This occurs due to the transformation of a neutron into a proton and an electron.

2. **Analyzing the Options**:
- **Option A: The valence shell of an atom**:
- This option refers to the outermost shell of electrons in an atom. Beta particles are not emitted from the valence shell; they are produced in the nucleus during nuclear reactions. Therefore, this option is incorrect.

- **Option B: The inner shell of an atom**:
- Similar to option A, the inner shell refers to electrons that are bound to the atom. The emission of beta particles does not occur from these shells either. Thus, this option is also incorrect.

- **Option C: The nucleus due to the nuclear conversion: Proton → Neutron + Electron**:
- This option suggests that a proton converts into a neutron and an electron. However, this is not the correct process for beta decay. The correct process involves a neutron decaying into a proton and an electron. Therefore, this option is incorrect.

- **Option D: The nucleus due to the nuclear conversion: Neutron → Proton + Electron**:
- This option correctly describes the process of beta decay. A neutron in the nucleus decays into a proton, emitting a beta particle (electron) in the process. This is the correct description of beta decay.

3. **Conclusion**:
- Based on the analysis of all options, the correct answer is **Option D**: The nucleus due to the nuclear conversion: Neutron → Proton + Electron.