Question

Which of the following statements is/are correct?

• A. The radial probability distribution curves for $2s$ atomic orbital has one trough representing a radial node
• B. The radial probability distribution curves for $2s$, $3p$ and $4d$ atomic orbitals are similar in shape
• C. The number of angular nodes cannot be found using radial distribution curves
• D. For $3s$ orbital the probability density is maximum at the nucleus.

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A The radial probability distribution curves for $2s$ atomic orbital has one trough representing a radial node
B The radial probability distribution curves for $2s$, $3p$ and $4d$ atomic orbitals are similar in shape
C The number of angular nodes cannot be found using radial distribution curves
D For $3s$ orbital the probability density is maximum at the nucleus.

The number of radial nodes for $2s$ orbital $=n-l-1=2-0-1=1$.

Since $2s$, $3p$ and $4d$ orbitals have the same number of radial nodes, the radial distribution curves have similar shapes. However, the principal maxima are at different radial distances from the nucleus.

Angular nodes or nodal planes have directional nature and hence angular part of the wavefunction should be employed to get information about them. The radial distribution curves have no clue about angular nodes.

For a spherical shaped orbitals, the probability density is maximum at the nucleus.
Hence all the statements are correct.