[Physics] How do orbitals exist in an atom

atomic-physicsatomsorbitalsquantum mechanics

I have come across a picture online which talks about 1s,2s,2p orbitals of a sodium atom.
enter image description here

Observation:In the picture we see some volume of space in common to two orbitals.

For example:The circled(red) region is common to both 1s and 2py orbitals

enter image description here

My opinion about the observation:
The common volume to two orbitals makes sense even when we consider the 3-Dimensional structure of an atom.

How it makes sense?

The S orbital is spherical in shape and P orbital is in dumb-bell shape.
So,some region of P orbital will lie in s orbital also(as both orbitals are present around the nucleus).

According to the knowledge I have in Quantum mechanics: An electron can occupy only one orbital at any given instant i.e for example,it can either be in 1s or 2p but definitely not in both the orbitals.This is because the two orbitals have quite different energies.

Question:

Please,explain the anomaly.

My level of knowledge: I can understand high school level Quantum mechanics and a little beyond.I can understand wave particle duality of matter and the concepts of probability densities.

Reference for the picture:

https://en.wikipedia.org/wiki/Atomic_orbital#/media/File:Schrodinger_model_of_the_atom.svg

Best Answer

There is a good answer here already, but there still seems to be some confusion, so I will give my input as well.

The regions in your diagrams correspond to the "most likely place to find the electron" if if was just in that state. Furthermore, the regions are defined by some threshold probability of finding the electron at that location. So technically, all orbitals "overlap", because the probability amplitude is defined for all of space. We just make these diagrams by only showing the most probable regions.

The issue you seem to be having is that the "location" of the electron determines which orbital it is in. The opposite is actually the case. The orbital that the electron is in determines it probability amplitude in the position basis.

Therefore, there are multiple reasons (probably more than I have just said) to be fine with "overlapping" orbitals

  1. The regions in the diagram correspond to single orbitals if the electron was only in that orbital (no superpositions)
  2. The regions in the diagram just show part of the probability density. Technically the probability density is defined in all space, so all orbitals "overlap" at all points in space
  3. The "location" of the electron does not determine which orbital it is in. If the electron is in some given orbital, we can then use the diagram to determine the most likely region the electron could be observed to be in.
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