In hydrogen spectrum, the series of lines appearing in ultra violet region of electromagnetic spectrum are called

Options

A. Balmer lines
B. Lyman lines
C. Pfund lines
D. Brackett lines.

Explanation

To solve the question regarding the series of lines appearing in the ultraviolet region of the electromagnetic spectrum in the hydrogen spectrum, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Hydrogen Spectrum**: The hydrogen spectrum consists of various series of spectral lines that result from electronic transitions between energy levels in a hydrogen atom.

2. **Identify the Regions of the Electromagnetic Spectrum**: The electromagnetic spectrum is divided into several regions, including ultraviolet (UV), visible, and infrared (IR) regions. Each series of lines in the hydrogen spectrum corresponds to transitions that occur in different regions.

3. **Recall the Different Series in Hydrogen Spectrum**:
- **Lyman Series**: This series corresponds to transitions where electrons fall to the first energy level (n=1) from higher levels (n=2, 3, 4, ...). The Lyman series is found in the ultraviolet region.
- **Balmer Series**: This series corresponds to transitions where electrons fall to the second energy level (n=2) from higher levels. The Balmer series is found in the visible region.
- **Paschen Series**: This series corresponds to transitions where electrons fall to the third energy level (n=3) from higher levels. The Paschen series is found in the infrared region.

4. **Determine the Correct Answer**: Since the question specifically asks for the series of lines that appear in the ultraviolet region, we identify that the Lyman series is the correct answer.

### Final Answer:
The series of lines appearing in the ultraviolet region of the electromagnetic spectrum in the hydrogen spectrum is called the **Lyman series**.

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