Question

Consider the following two statements Statement--I: The order of energies of \(2s\)-orbitals of H, Li and Na is \[ E_{2s}(\mathrm{H})<E_{2s}(\mathrm{Li})<E_{2s}(\mathrm{Na}) \] Statement--II: The photoelectric effect explains the wave nature of light. The correct answer is

• A. Both statements--I and II are correct
• B. Statement--I is correct but Statement--II is not correct
• C. Statement--I is not correct but Statement--II is correct
• D. Both statements--I and II are not correct \bigskip

Hint:

• Photoelectric effect proves the particle nature of light.
• Increasing nuclear charge lowers (makes more negative) the orbital energy.

Answer 1

The Correct Option is D

Step 1: Statement I: 2s energy becomes more negative with increasing Z. Given order reversed, so incorrect. Statement II: Photoelectric effect shows particle nature, not wave. Incorrect.

Step 2: Both incorrect. \(\boxed{\text{Both Statement--I and Statement--II are not correct}.}\)