# What is the structural difference between a 2P and a 3P orbital?

Jan 23, 2016

A $3 p$ orbital has a spherical node.

#### Explanation:

All $p$ orbitals have a characteristic dumbbell shape with a nodal plane perpendicular to the orbital axis.

We see this in the $2 p$ orbitals. (from chemwiki.ucdavis.edu)

The $3 p$ orbitals have the same general shape and are larger than $2 p$ orbitals, but they differ in the number of nodes.

You have probably noticed that the total number of nodes in an orbital is equal to $n - 1$, where $n$ is the principal quantum number.

Thus, a $2 p$ orbital has 1 node, and a $3 p$ orbital has 2 nodes.

Nodes can be either angular or radial.

The number of angular nodes is equal to $l$, where $l$ is the azimuthal quantum number.

Since all p orbitals have $l = 1$, they all have one angular node, and that is the nodal plane.

Radial nodes are spherical. The number of radial nodes is $n - 1 - l$.

Hence, a $2 p$ orbital has no radial nodes, while a $3 p$ orbital has one. (from www.villierspark.org.uk)

Here's a computer-generated image of the three $3 p$ orbitals without the spherical node drawn in. (from fineartamerica.com)

Can you see the spherical node?