Why is the s state spherically symmetric?

  • Context: Undergrad 
  • Thread starter Thread starter KFC
  • Start date Start date
  • Tags Tags
    State Symmetric
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
7 replies · 2K views
KFC
Messages
477
Reaction score
4
Hi there,
I am reading something about quantum numbers, there the author introduce the quantum number by solving Schrödinger equation for Hydrogen atom. It gives me an example when the principal quantum number n=4, there are four different sub-level ##s, p, d, f##. It also depicts the sublevel for them. It is said that for s state which ##\ell=0##, the shape is something like a completely flattened ellipse going through the nucleus. But since ##\ell=0##, there is no angular momentum, the electron is not "orbiting" anything; hence, it must be totally radially so s state is spherically symmetric.

It is quite confusing for me. Since it is said at the beginning it is flatten ellipse but later becomes spherically symmetric.

reference: http://web.pdx.edu/~pmoeck/lectures/312/chapter 7 part 3.doc
page 3 and page 8
 
Last edited:
Physics news on Phys.org
KFC said:
It is said that for s state which ##\ell=0##, the shape is something like a completely flattened ellipse going through the nucleus.
Where does your reference say that?
KFC said:
But since ##\ell=0##, there is no angular momentum, the electron is not "orbiting" anything; hence, it must be totally radially so s state is spherically symmetric.
Right. s orbitals are spherically symmetric.
 
Doc Al said:
Where does your reference say that?

Right. s orbitals are spherically symmetric.

Sorry that I give the wrong reference. I just get it corrected. And in the document given by the link, in page 3, note below the caption of FIGURE 7.3, it is said that "for l=0 we have a completely flattened ellipse that goes through the nucleus, this will be later called an s state."
 
Those elliptical orbits are remnants of the Bohr-Sommerfeld model of the atom. (Old stuff!) Note the diagram on page 20 of your reference, which shows the s orbitals as spherical.
 
  • Like
Likes   Reactions: KFC
KFC said:
Hi there,
I am reading something about quantum numbers, there the author introduce the quantum number by solving Schrödinger equation for Hydrogen atom. It gives me an example when the principal quantum number n=4, there are four different sub-level ##s, p, d, f##. It also depicts the sublevel for them. It is said that for s state which ##\ell=0##, the shape is something like a completely flattened ellipse going through the nucleus. But since ##\ell=0##, there is no angular momentum, the electron is not "orbiting" anything; hence, it must be totally radially so s state is spherically symmetric.

It is quite confusing for me. Since it is said at the beginning it is flatten ellipse but later becomes spherically symmetric.

reference: http://web.pdx.edu/~pmoeck/lectures/312/chapter 7 part 3.doc
page 3 and page 8
According to my prejudices, I always warn against physics manuscripts written with Word. This one cements my prejudice. SCNR.
 
Classically, an orbit with l=0 corresponds to the electron falling straight on or through the nucleus. Quantum mechanically, the orientation of this line becomes completely undetermined.