Which of the following statements are true ? (A) The subsidiary quantum number $l$ describes the shape of the orbital occupied by the electron. (B) (see structure) is the boundary surface diagram of the $2 \mathrm{p}_{\mathrm{x}}$ orbital. (C) The + and - signs in the wave function of the $2 \mathrm{p}_{\mathrm{x}}$ orbital refer to charge. (D) The wave function of $2 p_{x}$ orbital is zero everywhere in the xy plane.

JEE Main · 2025 · 02 Apr 2025 · Shift 2 · Atomic Structure

Which of the following statements are true ?
(A) The subsidiary quantum number

l

describes the shape of the orbital occupied by the electron.
(B) (see structure) is the boundary surface diagram of the

2 p_{x}

orbital.
(C) The + and - signs in the wave function of the

2 p_{x}

orbital refer to charge.
(D) The wave function of

2 p_{x}

orbital is zero everywhere in the xy plane.

Answer: (D)

The subsidiary (azimuthal) quantum number

l

fixes the shape of the orbital, so statement (A) is true. The dumb-bell boundary surface with its two lobes directed along the x-axis is the

2 p_{x}

orbital, so statement (B) is true. The

+

and

-

signs on the lobes denote the algebraic sign (phase) of the wave function, not electrical charge, so statement (C) is false. The

2 p_{x}

wave function is proportional to

x

and vanishes only where

x = 0

, that is throughout the yz plane and not the xy plane, so statement (D) is false. The correct statements are (A) and (B).

JEE Main · 2025 · 02 Apr 2025 · Shift 2 · Single correct option