For hydrogen atom, the orbital/s with lowest energy is/are :

Lowest Energy Orbitals in Hydrogen Atom | JEE Mains PYQ 2025 | Structure of Atom

Q. For hydrogen atom, the orbital/s with lowest energy is/are :

(A) 4s

(B) 3p_x

(D) 3d_z²

(E) 4p_z

Choose the correct answer from the options given below:

A. (A) only

B. (B) only

C. (B), (C) and (D) only

D. (A) and (E) only

Explanation

Step 1: Energy of orbitals in hydrogen atom

In hydrogen atom, energy depends only on principal quantum number n, not on l or orbital shape.

Step 2: Compare principal quantum number (n)

4s → n = 4
3p → n = 3
3d → n = 3
4p → n = 4

Step 3: Lowest energy condition

Lower value of n means lower energy.
All orbitals with n = 3 have lower energy than those with n = 4.

Step 4: Final selection

Orbitals with n = 3 are:
3p_x, 3d_x²−y², 3d_z²

Correct Answer = (B), (C) and (D) only

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