Which one of the series of hydrogen spectrum is in the visible region ?

Options

A. Lyman
B. Balmer
C. Paschen
D. Brackett

Explanation

To determine which series of the hydrogen spectrum is in the visible region, we can follow these steps:

### Step 1: Understand the Hydrogen Spectrum
The hydrogen spectrum consists of several series based on the electron transitions between energy levels. The main series include:
- Lyman series (n=1)
- Balmer series (n=2)
- Paschen series (n=3)
- Brackett series (n=4)
- Pfund series (n=5)

### Step 2: Identify the Visible Region
The visible region of the electromagnetic spectrum typically ranges from approximately 400 nm (violet) to 700 nm (red). We need to find which series has transitions that fall within this range.

### Step 3: Analyze the Balmer Series
The Balmer series corresponds to transitions where electrons fall to the n=2 energy level from higher energy levels (n=3, 4, 5, ...). The wavelengths of the emitted light in this series are:
- H-alpha (n=3 to n=2): 656 nm (red)
- H-beta (n=4 to n=2): 486 nm (blue-green)
- H-gamma (n=5 to n=2): 434 nm (blue)
- H-delta (n=6 to n=2): 410 nm (violet)

All these wavelengths fall within the visible spectrum.

### Step 4: Conclusion
Since the Balmer series includes transitions that result in wavelengths within the visible range, we conclude that the series of hydrogen spectrum that is in the visible region is the Balmer series.

### Final Answer
The Balmer series is the series of the hydrogen spectrum that is in the visible region.

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