Question #38976

1 Answer
Apr 27, 2016

There are two types of nodes: angular nodes and radial nodes.

Explanation:

An angular node is a planar or conical surface.

A radial node is a spherical surface surrounding the nucleus.

For a given orbital:

  • #"number of nodes" = n-1#
  • #"number of angular nodes" = l#
  • #"number of radial nodes" = n – l – 1#

For a #4s# orbital

#n = 4; l = 0#

  • #"number of nodes" = 4-1= 3#
  • #"number of angular nodes" = 0#
  • #"number of radial nodes" = 4 – 0 – 1 = 3#

A #4s# orbital has three radial nodes.

www.xn--ingenieurbro-richter-yec.de

A #4s# orbital has 3 radial nodes (the red vacancies between the blue occupied shells).

For a #4p_z# orbital

#n = 4; l = 1#

  • #"number of nodes" = 4-1= 3#
  • #"number of angular nodes" = 1#
  • #"number of radial nodes" = 4 – 1 – 1 = 2#

A #4p# orbital has one angular node and two radial nodes.

4p
(from fineartamerica.com)

The #4p_z# orbital has an angular node in the #xy# plane, with a small spherical node close to the nucleus and a larger one further out.

For a #4d_(xy)# orbital

#n = 4; l = 2#

  • #"number of nodes" = 4-1= 3#
  • #"number of angular nodes" = 2#
  • #"number of radial nodes" = 4 – 2 – 1 = 1#

A #4d_(xy)# orbital has two angular nodes and one radial node.

4d
(from fineartamerica.com)

The #4d_(xy)# orbital is the one on the top left, but it is easier to see the nodes in the #4d_(xz)# orbital at top centre.

The latter has two angular nodes (the #xy# and #yz# planes) and a radial (spherical) node.