In a hydrogen atom, which orbital is higher in energy than a 3s-orbital?

Options

A. 2s
B. 3p
C. 3d
D. 4s

Answer

To determine which orbital is higher in energy than a 3s orbital in a hydrogen atom, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Hydrogen Atom Energy Levels**:
- In a hydrogen atom (or hydrogen-like atoms), the energy of an orbital is primarily determined by its principal quantum number (n).

2. **Identify the Principal Quantum Number of 3s**:
- The 3s orbital has a principal quantum number (n) of 3.

3. **Compare with Other Orbitals**:
- To find an orbital with a higher energy than 3s, we need to look for orbitals with a principal quantum number greater than 3.
- The next principal quantum number is 4, which corresponds to the 4s orbital.

4. **Conclusion**:
- The 4s orbital has a principal quantum number (n) of 4, which is higher than the 3s orbital. Therefore, the 4s orbital is higher in energy than the 3s orbital.

### Final Answer:
The orbital that is higher in energy than a 3s orbital in a hydrogen atom is the **4s orbital**.

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