Which transitions are responsible for the occurrence of Brackett series in the spectrum of hydrogen?

Answer

To determine which transitions are responsible for the occurrence of the Brackett series in the spectrum of hydrogen, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Brackett Series**:
The Brackett series is a set of spectral lines in the hydrogen spectrum that corresponds to electronic transitions between energy levels. Specifically, it involves transitions to the energy level n = 4.

2. **Identifying the Energy Levels**:
In the Brackett series, the transitions occur from higher energy levels (n = 5, 6, 7, 8, ...) down to the energy level n = 4.

3. **Describing the Transitions**:
The transitions responsible for the Brackett series can be described as follows:
- Transition from n = 5 to n = 4
- Transition from n = 6 to n = 4
- Transition from n = 7 to n = 4
- Transition from n = 8 to n = 4
- And so on for higher energy levels.

4. **Energy Emission**:
When an electron transitions from a higher energy level to a lower energy level (in this case, from n = 5, 6, 7, or 8 to n = 4), energy is emitted in the form of light. This emitted light corresponds to specific wavelengths.

5. **Wavelength Region**:
The wavelengths of the emitted light in the Brackett series fall within the infrared region of the electromagnetic spectrum.

### Conclusion:
The transitions responsible for the occurrence of the Brackett series in the spectrum of hydrogen are:
- From n = 5 to n = 4
- From n = 6 to n = 4
- From n = 7 to n = 4
- From n = 8 to n = 4
- And higher levels transitioning to n = 4.