In the line spectrum of hydrogen, the lines described by the formula
`v= 109,677 {1/2^2-1/n^2}cm^-1` where, n = integer, `n ge3 constitutes`

Options

A. Balmer series
B. Lyman series
C. Pfund series
D. Paschen series

Answer

To solve the question regarding the line spectrum of hydrogen and the given formula, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Formula**:
The formula provided is:
\[ v = 109,677 \left( \frac{1}{2^2} - \frac{1}{n^2} \right) \text{ cm}^{-1} \]
Here, \( v \) represents the wave number, and \( n \) is an integer greater than or equal to 3.

2. **Identify the Series**:
The formula indicates that the transition involves an electron moving from a higher energy level (n) to a lower energy level (2). This corresponds to the Balmer series, which is characterized by transitions to the second energy level (n=2).

3. **Determine the Values of n**:
Since \( n \) must be an integer greater than or equal to 3, the possible values for \( n \) are 3, 4, 5, etc. The transitions will be:
- For \( n = 3 \): Transition from n=3 to n=2
- For \( n = 4 \): Transition from n=4 to n=2
- For \( n = 5 \): Transition from n=5 to n=2
- And so on.

4. **Identify the Series Name**:
The transitions from higher levels (n ≥ 3) to n=2 correspond to the Balmer series. The series that corresponds to transitions from n=3, n=4, etc., to n=2 is known as the Balmer series.

5. **Conclusion**:
Thus, the lines described by the formula correspond to the Balmer series of hydrogen.

### Final Answer:
The lines described by the formula correspond to the Balmer series of hydrogen.

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