Question

Which one of the following statements in relation to the hydrogen atom is correct?

• A. 3s, 3p, and 3d orbitals all have the same energy.
• B. 3s and 3p orbitals are of lower energy than 3d orbital.
• C. 3p orbital is lower in energy than 3d orbital.
• D. 3s orbital is lower in energy than 3p orbital.

Hint:

In a hydrogen atom, the energy of orbitals depends only on the principal quantum number \( n \). All orbitals with the same \( n \) (3s, 3p, 3d) have the same energy.

Answer 1

The Correct Option is A

In the hydrogen atom, the energy levels of orbitals are determined solely by the principal quantum number \( n \). The hydrogen atom does not have electron-electron repulsion, so the energy of orbitals with the same principal quantum number \( n \) (like 3s, 3p, and 3d) are degenerate, meaning they have the same energy. 
- Option A: This is correct because in the hydrogen atom, orbitals with the same \( n \) (such as 3s, 3p, and 3d) have the same energy, as the energy depends only on the principal quantum number, not the type of orbital (s, p, or d). 
- Option B: This is incorrect. While in multi-electron atoms, the 3s and 3p orbitals are lower in energy than the 3d orbital, in the case of the hydrogen atom, all the 3 orbitals (3s, 3p, and 3d) have the same energy. 
- Option C: This is incorrect for the hydrogen atom. All the orbitals with the same principal quantum number have the same energy. 
- Option D: This is incorrect for the hydrogen atom. The energy of the 3s orbital is not necessarily lower than the 3p orbital; both have the same energy in a hydrogen atom. Thus, the correct statement is Option A.