Which of the following series of H-atom lies in visible range?

Options

A. Paschen
B. Balmer
C. Lymen
D. Pfund

Answer

To determine which series of the hydrogen atom lies in the visible range, we can analyze the different series of spectral lines produced by hydrogen transitions:

### Step 1: Identify the series of hydrogen atom
The hydrogen atom exhibits several series based on the transitions of electrons between energy levels. The main series are:
- Lyman series
- Balmer series
- Paschen series
- Brackett series
- Pfund series

### Step 2: Determine the wavelength ranges for each series
Each series corresponds to a specific range of wavelengths:
- **Lyman series**: Transitions to the n=1 level, lies in the ultraviolet (UV) region (wavelengths < 400 nm).
- **Balmer series**: Transitions to the n=2 level, lies in the visible region (wavelengths approximately 400 nm to 700 nm).
- **Paschen series**: Transitions to the n=3 level, lies in the infrared region (wavelengths > 700 nm).
- **Brackett series**: Transitions to the n=4 level, also in the infrared region.
- **Pfund series**: Transitions to the n=5 level, in the infrared region as well.

### Step 3: Identify which series lies in the visible range
From the analysis above, we can conclude that the **Balmer series** is the only series that lies in the visible range.

### Final Answer
The series of the hydrogen atom that lies in the visible range is the **Balmer series**.

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