Which of the following is true?

Options

A. Lyman series is a continuous spectrum
B. Paschen series is a line spectrum in the infrared
C. Balmer series is a line spectrum in the ultraviolet
D. The spectral series formula can be derived from the Rutherford model of the hydrogen atom

Answer

To determine which of the statements regarding the hydrogen atom and its spectral series is true, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement 1: Lyman series lies in the UV region.**
- The Lyman series corresponds to transitions of electrons from higher energy levels (n ≥ 2) to the n=1 level. This series emits ultraviolet radiation.
- **Conclusion:** This statement is **true**.

2. **Statement 2: Lyman series lies in the continuous spectrum.**
- The Lyman series consists of discrete spectral lines, not a continuous spectrum.
- **Conclusion:** This statement is **false**.

3. **Statement 3: Paschen series lies in the infrared region.**
- The Paschen series corresponds to transitions from higher energy levels to the n=3 level and is indeed in the infrared region.
- **Conclusion:** This statement is **true**.

4. **Statement 4: Balmer series lies in the visible region.**
- The Balmer series corresponds to transitions from higher energy levels to the n=2 level and falls within the visible spectrum.
- **Conclusion:** This statement is **true**.

5. **Statement 5: The spectral series formula can be derived from the Rutherford model of the hydrogen atom.**
- The Rutherford model does not adequately explain the spectral lines of hydrogen. The Bohr model is the one that provides a formula for the spectral series.
- **Conclusion:** This statement is **false**.

### Summary of Findings:
- True Statements:
- Lyman series lies in the UV region (Statement 1).
- Paschen series lies in the infrared region (Statement 3).
- Balmer series lies in the visible region (Statement 4).

- False Statements:
- Lyman series lies in the continuous spectrum (Statement 2).
- The spectral series formula can be derived from the Rutherford model (Statement 5).

### Final Answer:
The true statements are:
- Lyman series lies in the UV region.
- Paschen series lies in the infrared region.
- Balmer series lies in the visible region.