Which spectral series of hydrogen atom lie in the ultraviolet region ?

Options

A. Lyman
B. Paschen
C. P Fund
D. Balmer

Answer

To determine which spectral series of the hydrogen atom lies in the ultraviolet region, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Spectral Series**: The hydrogen atom has six main spectral series based on the transitions of electrons between energy levels. These series are:
- Lyman series
- Balmer series
- Paschen series
- Brackett series
- Pfund series
- Humphreys series

2. **Identify the Regions of the Electromagnetic Spectrum**:
- **Ultraviolet Region**: Wavelengths from about 10 nm to 400 nm.
- **Visible Region**: Wavelengths from about 400 nm to 700 nm.
- **Infrared Region**: Wavelengths longer than 700 nm.

3. **Locate Each Series in the Spectrum**:
- **Lyman Series**: Transitions to the n=1 level (ultraviolet region).
- **Balmer Series**: Transitions to the n=2 level (visible region).
- **Paschen Series**: Transitions to the n=3 level (infrared region).
- **Brackett Series**: Transitions to the n=4 level (infrared region).
- **Pfund Series**: Transitions to the n=5 level (far infrared region).
- **Humphreys Series**: Transitions to the n=6 level (far infrared region).

4. **Conclusion**: From the above analysis, we can conclude that the **Lyman series** is the only spectral series of the hydrogen atom that lies in the ultraviolet region.

### Final Answer:
The spectral series of the hydrogen atom that lies in the ultraviolet region is the **Lyman series**.

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