An electron in hydrogen jumps to a shell in which four fold degeneracy is present , then correct about that shell is

Options

A. 3
B. 4
C. 2
D. This type of transition is not possible

Answer

To solve the question regarding the electron in hydrogen jumping to a shell with four-fold degeneracy, we need to analyze the degeneracy of the orbitals in hydrogen and understand the concept of electron transitions.

### Step-by-Step Solution:

1. **Understanding Degeneracy**:
- Degeneracy refers to the number of orbitals that have the same energy level. In hydrogen, the degeneracy of orbitals is determined by the azimuthal quantum number (l).
- The possible values of l are:
- For s orbitals (l = 0): 1 orbital (no degeneracy)
- For p orbitals (l = 1): 3 orbitals (three-fold degeneracy)
- For d orbitals (l = 2): 5 orbitals (five-fold degeneracy)
- For f orbitals (l = 3): 7 orbitals (seven-fold degeneracy)

2. **Identifying Four-Fold Degeneracy**:
- The question specifies that the electron jumps to a shell with four-fold degeneracy. However, based on the above information, there are no orbitals in hydrogen that exhibit four-fold degeneracy.
- The only degeneracies present in hydrogen are:
- 1 for s (l=0)
- 3 for p (l=1)
- 5 for d (l=2)
- 7 for f (l=3)

3. **Conclusion**:
- Since there are no orbitals with four-fold degeneracy in hydrogen, the transition to such a shell is not possible. Therefore, the correct answer to the question is that this type of transition is not possible.

### Final Answer:
- The correct option is D: This type of transition is not possible.