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all about nodes..............sssssssseeeeeeeeeee

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posted on 26 Jul 2007 10:00:46 IST

The wave nature of the electron is what makes atoms have the properties that they do. It explains the colors of the atoms and also their size. It also means that we cannot think about the electron in an atom as a little ball whirling about the nucleus, but a cloud of probability that is smeared out over the orbit.

This cloud is only spherical for the lowest energy level of the atom. As the energy of the electron in the atom increases, its wavelength decreases, and the number of times the wave amplitude crosses zero per orbit increases. Again, these zero crossings are called nodes. The number of nodes is related to the frequency of the wave and therefore its energy.
The greater number of nodes, the greater the energy of the system.
The lowest level of the H atom has no (zero) nodes, the next higher level has 1 node, but that node can either be an angular node or a radial node. If it is an angular node, then you have a 2p orbital

If you have a radial node, then you have a 2s orbital (3s shown also)

The number of nodes determines the energy. The Principle quantum number, n, is equal to the number of nodes plus 1, i.e. nodes = n-1. For a hydrogen atom, the energy it takes to make a radial node is equal to the the energy it takes to make an angular node.

For higher n, you can have a greater numbers of nodes. For n>=3, you can have 2 angular nodes, and these are called d orbitals
Here are some more pictures of the atomic orbital shapes

The following shows the angular nodes for a 2p orbital:

Similarly for a 3d orbital (with two angular nodes):

In short, the energy of the atom is determined by the number of nodes which is related to the principal quantum number n by: nodes = n-1.
The number of angular nodes is labelled by a letter (s, p, d, f, g, h, i, ....)

s: no angular nodes
p: one angular node
d: two angular nodes
f: three angular nodes
etc...

Note: The number of radial nodes is the total number of nodes minus the number of angular nodes.

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comment by nivedh_89 (posted on 26 Jul 2007 10:22:50 IST)

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comment by seriousstone89 (posted on 26 Jul 2007 11:20:31 IST)

great work....from where did you get these things?

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comment by nivedh_89 (posted on 26 Jul 2007 11:30:52 IST)

hey....it has been forwarded to me when i wanted it the most..........i thought it will be useful to goiitians also...............

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comment by seriousstone89 (posted on 26 Jul 2007 11:35:06 IST)

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comment by nivedh_89 (posted on 26 Jul 2007 11:37:24 IST)

ur welcome............

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comment by kishan12 (posted on 26 Jul 2007 22:14:01 IST)

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