An electrons in a hydrogen atom finds itself in the fourth energy level.
(i) Write down a list of the orbits that it might be in.
(ii) Can it be in all of these orbitals at once?
(iii) Can you tell which orbital it is in ?

Explanation

To solve the question step by step, we will address each part of the question regarding the electron in a hydrogen atom that is in the fourth energy level.

### Step-by-Step Solution:

**(i) List of Orbits:**
The electron in a hydrogen atom that is in the fourth energy level corresponds to the principal quantum number \( n = 4 \). The possible orbitals (subshells) for this energy level are:
- 4s
- 4p
- 4d
- 4f

Thus, the list of orbits that the electron might be in is:
- 4s
- 4p
- 4d
- 4f

**(ii) Can it be in all of these orbitals at once?**
No, the electron cannot occupy all of these orbitals at once. According to quantum mechanics, an electron in an atom can only exist in one specific orbital at any given time. Therefore, it will be in one of the orbitals listed above, but not in all of them simultaneously.

**(iii) Can you tell which orbital it is in?**
No, we cannot determine which specific orbital the electron is in. In a hydrogen atom, all orbitals with the same principal quantum number \( n \) (in this case, \( n = 4 \)) have the same energy. This means that the 4s, 4p, 4d, and 4f orbitals are degenerate (they have the same energy). Because of this degeneracy, it is impossible to specify which orbital the electron occupies without additional information.

### Summary of Answers:
1. The possible orbits are: 4s, 4p, 4d, 4f.
2. No, it cannot be in all of these orbitals at once.
3. No, we cannot tell which orbital it is in.