Node

Definition

A node is a point in an atomic or molecular orbital where the probability of finding an electron is zero. Nodes can be classified as either radial or angular depending on their nature.

5 Must Know Facts For Your Next Test

1. Nodes are regions where the wave function, and therefore electron density, is zero.
2. In a $p$-orbital, there is one nodal plane passing through the nucleus.
3. The number of nodes in an orbital is given by $n - l - 1$, where $n$ is the principal quantum number and $l$ is the azimuthal quantum number.
4. Radial nodes occur at certain distances from the nucleus and are spherical in shape.
5. Angular nodes are defined by specific angles and result in planar or conical shapes.

Review Questions

• What defines a node in an atomic or molecular orbital?
• How do you calculate the number of nodes in an orbital using quantum numbers?
• What distinguishes radial nodes from angular nodes?

Related terms

Orbital:

A region around an atom's nucleus where there is a high probability of finding electrons.

$p$-Orbital: $p$-orbitals have one nodal plane and can hold up to six electrons within three sub-orbitals.

$d$-Orbital: $d$-orbitals have two nodal planes and can hold up to ten electrons within five sub-orbitals.