JEE Chemistry 2025 Question with Solution

Given:

• Statement (I): A spectral line will be observed for a $2p_x \rightarrow 2p_y$ transition.
• Statement (II): $2p_x$ and $2p_y$ are degenerate orbitals.

Find: Which statement combination is correct.

A spectral line is observed only when a transition involves a non-zero energy difference so that a photon is emitted or absorbed.

Here, $2p_x$ and $2p_y$ are degenerate orbitals, so their energies are equal.

Since $\Delta E = 0$, no photon is emitted or absorbed for the $2p_x \rightarrow 2p_y$ transition. Therefore, Statement (I) is false.

Also, $2p_x$ and $2p_y$ belong to the same $2p$ subshell and are degenerate in energy. Therefore, Statement (II) is true.

Hence, the correct option is B: Statement I is false but Statement II is true.

Given: The question asks about a possible spectral line for transition between $2p_x$ and $2p_y$ and about degeneracy of these orbitals.

Find: Truth values of Statement (I) and Statement (II).

Spectral lines arise from transitions between states having different energies. The photon energy is given by

For $2p_x$ and $2p_y$, the energy is the same because these orbitals are degenerate.

Thus,

So, no radiation corresponding to a spectral line is produced for a transition between them. This makes Statement (I) false.

Since orbitals with the same energy are called degenerate orbitals, Statement (II) is true.

Therefore, the correct option is B.