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Physics/Shielding effect on nuclear charge

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Question
Why is the shielding effect of orbitals in the order s>p>d>f? i.e. why are s orbitals most effective and p orbitals least effective for shielding or screening nuclear charge?

Answer
Dear Sriram:

The key here is the shape of the orbital (http://www.d.umn.edu/~pkiprof/ChemWebV2/AOs/)
and to a degree how closs the orbital is to the nucleus.

S orbitals are spherical and shield equally well in all directions, pretty much at full strength.  They are also (all other things being equal) closer to the nucleus.

P orbitals are split into two lobes that only block one axis, so they cannot shield in all directions at once.  They also tend to be further out in space than the s orbitals, making it more likely that a charge can 'feel' the nucleus from more directions and greater distances.

D orbitals are split into four lobes (mostly) and only protect along a given plane - they also tend to stick out even further than s and p orbitals.  This makes them even worse at shielding than p orbitals.

F orbitals stick out the most and have lots of lobes, making them the worst at shielding out of all of the orbitals.

I hope this helps!

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Dr. Jeffery Raymond

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Materials chemistry. Materials science. Spectroscopy. Polymer science. Physical Chemistry. General Physics. Technical writing. General Applied Mathematics. Nanomaterials. Optoelectronic Behavior. Science Policy.

Experience

Teaching: General Inorganic Chemistry I & II, Organic Chemistry I & II, Physical Chemistry I, Polymeric Materials, General Physics I, Calculus I & II
My prior experience includes the United States Army and three years as a development chemist in industry. Currently I am the Assistant Director of the Laboratory for Synthetic Biological Interactions. All told, 13 years of experience in research, development and science education.

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Texas A&M University, American Chemical Society, POLY-ACS, SPIE

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Journal of the American Chemical Society, Nanoletters, Journal of Physical Chemistry C, Journal of Physical Chemistry Letters, Ultramicroscopy Proceedings of SPIE, Proceedings of MRS, Polymer News, Chemical and Engineering News, Nano Letters, Small, Chemistry.org, Angewandte

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PhD Macromolecular Science and Engineering (Photophysics/Nanomaterials Concentration), MS Materials Science, BS Chemistry and Physics, Graduate Certificate in Science Policy, AAS Chemical Technology, AAS Engineering Technology

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