Which of the following spectral series falls within the visible range of electromagnetic radiation ?

Options

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

Explanation

To determine which spectral series falls within the visible range of electromagnetic radiation, we can follow these steps:

### Step 1: Understand the Spectral Series
The spectral series of hydrogen includes:
- Lyman series
- Balmer series
- Paschen series
- Brackett series

Each of these series corresponds to electron transitions in the hydrogen atom.

### Step 2: Identify the Wavelength Ranges
- **Lyman Series**: Transitions to the n=1 level; emits ultraviolet radiation (wavelength < 400 nm).
- **Balmer Series**: Transitions to the n=2 level; emits visible light (wavelength range: 380 nm to 700 nm).
- **Paschen Series**: Transitions to the n=3 level; emits infrared radiation (wavelength > 700 nm).
- **Brackett Series**: Transitions to the n=4 level; emits infrared radiation (wavelength > 700 nm).

### Step 3: Determine the Visible Range
The visible range of electromagnetic radiation is approximately from 380 nm to 700 nm.

### Step 4: Analyze Each Series
- Lyman series: Not in the visible range (UV).
- Balmer series: Falls within the visible range.
- Paschen series: Not in the visible range (IR).
- Brackett series: Not in the visible range (IR).

### Step 5: Conclusion
The only spectral series that falls within the visible range of electromagnetic radiation is the **Balmer series**.

### Final Answer
**The Balmer series falls within the visible range of electromagnetic radiation.**

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