Question

For radial probability curves, which of the following is/are correct?

• A. The number of maxima in $2s$ orbital are two
• B. The number of spherical or radial nodes is equal to $n-l-1$
• C. The number of angular nodes are ${}^{\prime }{l}^{\prime }$
• D. $3d_z^2$ has 3 angular nodes

Answer 1

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

The correct options are
A The number of spherical or radial nodes is equal to $n-l-1$
B The number of angular nodes are ${}^{\prime }{l}^{\prime }$
C The number of maxima in $2s$ orbital are two

There are two types of nodes, angular and radial nodes. Angular nodes are typically flat plane (at fixed angles), like those in the diagram above. The l quantum number determines the number of angular nodes in an orbital. Radial nodes are spheres (at fixed radius) that occurs as the principal quantum number increases. The total nodes of an orbital are the sum of angular and radial nodes and are given in terms of $n$ and $l$ quantum number by the following equation:

$N=n-l-1$

1. Option A is correct as per given above image.
2. Option B is correct as the number of radial or spherical nodes is given by '$n-1$'.
3. Option C is correct.
4. Option D is wrong. It has 2 angular nodes.

Hence, Option A,B,C are correct.