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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: 5416339 on July 14, 2010, 05:23:19 AM

Title: What is a radial Node ? What is an Angular Node ?
Post by: 5416339 on July 14, 2010, 05:23:19 AM
Can anyone give me a picture of what the above terms mean..I know the mathematical meaning like

But i want to know like how and what exactly is a radial node and an angular node !
 
The node of an S sub shell  is easy but where are the nodes in the P and d Sub shell ? And please explain what radial node and angular node mean..Thanks !
Title: Re: What is a radial Node ? What is an Angular Node ?
Post by: tamim83 on July 17, 2010, 11:17:02 AM
Here is a nice website that has pictures of many of the different atomic orbitals.  http://winter.group.shef.ac.uk/orbitron/

Pictorally, a radial node appears to be a spherical surface in which there is no electron density and the sign of the wavefunction changes.  Yes, for s orbitals this is easy since they are spherical in shape already.  If you look at the 3p orbital, you'll see what appears to be a "mini" p orbital in the center surrounded by two other "lobes".  The boundary between the inner and outer lobes is the radial node.   If you look at the 4p orbital there will be one more set of lobes and so on.  There is something similar going on with the d and f orbitals, but its more complex.  There are n - l - 1 radial nodes for a subshell. 

An angular node is usually a planar or conical surface in which there is no electron density.  The p orbitals have a planar node through the center, d orbitals have two conical nodes for the dz2 (imagine drawing cones around nodes of the same sign and those are the conical angular nodes) and 2 planar nodes for the rest , and so on.  The number of angular nodes matches the l quantum number for the subshell. 

Hope this helps you some.