Given below are two statements : Statement (I) : A spectral line will be observed for a 2 p_x arrow 2 p_y transition. Statement (II) : 2 p_x and 2 p_y are degenerate orbitals. In the light of the above statements, choose the correct answer from the options given below :

Statement I is false but Statement II is true

Both Statement I and Statement II are false

Statement I is true but Statement II is false

Both Statement I and Statement II are true

Structure of Atom PYQ — JEE Main 2025 · 22 Jan · Shift 2 · Q19 with Solution

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Correct answer: A

Analyze Statement (I):

The transition mentioned is: $2p_x \rightarrow 2p_y$

Now, $2p_x$ and $2p_y$ are orbitals belonging to the same subshell ( $2p$ ). In the absence of an external field, all three $2p$ orbitals ( $2p_x, 2p_y, 2p_z$ ) have the same energy.

Therefore, $E(2p_x)=E(2p_y)$ so the energy difference is $\Delta E = 0$

A spectral line is observed only when radiation of nonzero frequency is emitted or absorbed: $\Delta E = h\nu$

If $\Delta E = 0$ , then $\nu = 0$ which does not correspond to an observable spectral line.

Also, such a transition between degenerate orbitals of the same shell is not observed as an electronic spectral transition.

Hence, Statement (I) is false.
Analyze Statement (II):

The orbitals $2p_x$ and $2p_y$ differ only in orientation in space. For an isolated atom, their energies are identical.

Therefore, they are degenerate orbitals.

Hence, Statement (II) is true.
Choose the correct option:
- Statement I: False
- Statement II: True
So the correct option is: $\boxed{\text{A}}$
Comparison with stored answer:

Stored correct answer = A

My derived answer also = A, so they agree.