Question

The correct statement about probability density (except at infinite distance from nucleus) is :

• A. It can be zero for 1s orbital
• B. It can be zero for 3p orbital
• C. It can never be zero for 2s orbital
• D. It can negative for 2p orbital

Hint:

Probability density is psi squared, so it is never negative; it is zero at nodes. Radial nodes = n - l - 1.

Answer 1

The Correct Option is B

Probability density = \(\psi^2\) is zero at nodes (radial or angular) and can never be negative.
Radial nodes = n - l - 1:
1s: 0 radial nodes, so \(\psi^2\) is never zero (at finite r); option (1) is false.
3p: 3 - 1 - 1 = 1 radial node, so \(\psi^2\) is zero at that radius; option (2) is true.
2s: 2 - 0 - 1 = 1 radial node, so \(\psi^2\) is zero there; option (3) is false.
2p: probability density cannot be negative; option (4) is false.
Answer: (2) It can be zero for 3p orbital