Increase in atomic number is observed during:

Options

A. Alpha emission
B. Beta emission
C. Positron emission
D. Electron capture

Answer

To solve the question regarding the increase in atomic number during certain nuclear processes, we will analyze the different types of emissions and their effects on atomic and mass numbers.

### Step-by-Step Solution:

1. **Understanding Atomic and Mass Numbers**:
- The atomic number (Z) represents the number of protons in an atom's nucleus.
- The mass number (A) is the total number of protons and neutrons in the nucleus.

2. **Identifying Types of Emissions**:
- We will consider four types of emissions: alpha emission, beta emission, positron emission, and electron capture.

3. **Alpha Emission**:
- In alpha emission, an alpha particle (which is equivalent to a helium nucleus) is emitted.
- This results in:
- Atomic number decreases by 2 (Z → Z - 2)
- Mass number decreases by 4 (A → A - 4)
- **Conclusion**: No increase in atomic number.

4. **Beta Emission**:
- In beta emission, a beta particle (electron) is emitted.
- This results in:
- Atomic number increases by 1 (Z → Z + 1)
- Mass number remains the same (A → A)
- **Conclusion**: There is an increase in atomic number.

5. **Positron Emission**:
- In positron emission, a positron (the antimatter counterpart of an electron) is emitted.
- This results in:
- Atomic number decreases by 1 (Z → Z - 1)
- Mass number remains the same (A → A)
- **Conclusion**: No increase in atomic number.

6. **Electron Capture**:
- In electron capture, an electron is captured by the nucleus.
- This results in:
- Atomic number decreases by 1 (Z → Z - 1)
- Mass number remains the same (A → A)
- **Conclusion**: No increase in atomic number.

7. **Final Conclusion**:
- The only process that results in an increase in atomic number is **beta emission**. Therefore, the correct answer to the question is **beta emission**.

### Summary of Findings:
- **Alpha Emission**: Z decreases by 2, A decreases by 4 (No increase)
- **Beta Emission**: Z increases by 1, A remains the same (Increase)
- **Positron Emission**: Z decreases by 1, A remains the same (No increase)
- **Electron Capture**: Z decreases by 1, A remains the same (No increase)

### Answer:
The increase in atomic number is observed during **beta emission**.

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