visible line of hydrogen spectrum will be

Options

A. lyman
B. balmer
C. brackett
D. pfund

Answer

To determine the visible lines of the hydrogen spectrum, we need to identify which series of spectral lines fall within the visible range of wavelengths, which is approximately 400 nm to 700 nm.

**Step-by-step Solution:**

1. **Understanding the Hydrogen Spectrum:**
The hydrogen spectrum consists of several series of spectral lines corresponding to electron transitions between energy levels. The main series are:
- Lyman series (n=1)
- Balmer series (n=2)
- Paschen series (n=3)
- Brackett series (n=4)
- Pfund series (n=5)

2. **Identifying the Visible Range:**
The visible range of light is from approximately 400 nm (violet) to 700 nm (red). We need to find out which series has lines that fall within this range.

3. **Analyzing Each Series:**
- **Lyman Series:** Transitions to n=1 (all lines are in the ultraviolet range, < 400 nm).
- **Balmer Series:** Transitions to n=2 (includes visible lines).
- **Paschen Series:** Transitions to n=3 (all lines are in the infrared range, > 700 nm).
- **Brackett Series:** Transitions to n=4 (also in the infrared range).
- **Pfund Series:** Transitions to n=5 (also in the infrared range).

4. **Identifying the Balmer Series:**
The Balmer series is characterized by transitions from higher energy levels (n=3, 4, 5, ...) to n=2. The wavelengths of the first few lines of the Balmer series are:
- H-alpha (n=3 to n=2) = 656.3 nm (red)
- H-beta (n=4 to n=2) = 486.1 nm (blue-green)
- H-gamma (n=5 to n=2) = 434.0 nm (blue)
- H-delta (n=6 to n=2) = 410.2 nm (violet)

All these lines fall within the visible range.

5. **Conclusion:**
Since the only series that has spectral lines falling within the visible range (400 nm to 700 nm) is the Balmer series, we conclude that the visible lines of the hydrogen spectrum are from the Balmer series.

**Final Answer:**
The visible lines of the hydrogen spectrum will be from the Balmer series.

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