The value of `n_(1)` for Paschen series of hydrogen spectrum is`(n_(1) =` orbit number in which electron falls)

Options

A. 1
B. 2
C. 3
D. 4

Answer

To determine the value of \( n_1 \) for the Paschen series of the hydrogen spectrum, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Series**:
The hydrogen spectrum consists of several series based on the energy levels from which electrons transition. The main series are:
- Lyman series
- Balmer series
- Paschen series
- Bracket series
- Pfund series

2. **Identifying \( n_1 \) for Each Series**:
Each series has a specific value of \( n_1 \), which is the principal quantum number of the lower energy level (the level to which the electron falls). The values are as follows:
- Lyman series: \( n_1 = 1 \)
- Balmer series: \( n_1 = 2 \)
- Paschen series: \( n_1 = 3 \)
- Bracket series: \( n_1 = 4 \)
- Pfund series: \( n_1 = 5 \)

3. **Finding \( n_1 \) for the Paschen Series**:
From the information above, we can see that for the Paschen series, the electron transitions to the third energy level. Therefore, the value of \( n_1 \) for the Paschen series is:
\[ n_1 = 3 \]

4. **Conclusion**:
Thus, the value of \( n_1 \) for the Paschen series of the hydrogen spectrum is \( 3 \).

### Final Answer:
\[ n_1 = 3 \]