The mass of a proton is `1836` times more than the mass of an electron. It a sub-atomic of mass `(m) 207` times the mass of electron is captured by the nucleus, then the first ionization potential of `H`:

Options

A. decreases
B. increases
C. remains same
D. may be decreases ot increase

Explanation

To solve the problem, we need to determine how the first ionization potential of hydrogen changes when a subatomic particle of mass \( m \) (207 times the mass of an electron) is captured by the nucleus.

### Step-by-Step Solution:

1. **Understand the Masses Involved**:
- The mass of a proton (\( m_p \)) is given as \( 1836 \) times the mass of an electron (\( m_e \)).
- The mass of the subatomic particle (\( m \)) is given as \( 207 \) times the mass of an electron.

2. **Express the Masses**:
- Let \( m_e \) be the mass of the electron.
- Then, \( m_p = 1836 \times m_e \).
- The mass of the subatomic particle is \( m = 207 \times m_e \).

3. **Calculate the Reduced Mass**:
- The reduced mass (\( \mu \)) of the system consisting of the proton and the captured subatomic particle can be calculated using the formula:
\[ \mu = \frac{m_p \cdot m}{m_p + m} \]
- Substituting the values:
\[ \mu = \frac{(1836 \times m_e) \cdot (207 \times m_e)}{(1836 \times m_e) + (207 \times m_e)} \]

4. **Simplify the Expression**:
- Factor out \( m_e \) from the numerator and denominator:
\[ \mu = \frac{1836 \cdot 207 \cdot m_e^2}{(1836 + 207) \cdot m_e} \]
- This simplifies to:
\[ \mu = \frac{1836 \cdot 207 \cdot m_e}{1836 + 207} \]

5. **Calculate the Total Mass**:
- Calculate \( 1836 + 207 = 2043 \).
- Now, substituting this back into the equation gives:
\[ \mu = \frac{1836 \cdot 207 \cdot m_e}{2043} \]

6. **Determine the Ionization Potential**:
- The ionization potential (\( I \)) is directly proportional to the reduced mass (\( \mu \)):
\[ I \propto \mu \]
- Since the reduced mass has increased due to the addition of the subatomic particle, the ionization potential of hydrogen will also increase.

7. **Conclusion**:
- Therefore, the first ionization potential of hydrogen will increase.

### Final Answer:
The first ionization potential of hydrogen will increase.