How does 2s orbital differ from 1s?

1 Answer
May 28, 2018

A #2s# orbital has one more radial node.


The number of total nodes is

#n-1#,

where #n# is the principal quantum number (#n = 1, 2, 3, . . . #).

The number of angular nodes is given by #l#, the angular momentum quantum number, so the number of radial nodes is

#n - l - 1#.

But for #s# orbitals, #l = 0#, so #n - 1 = n - l - 1# for #s# orbitals. Therefore, since #n# increased by #1#, #2s# orbitals have one more node, and it is of the radial kind.

https://qph.fs.quoracdn.net/

Knowing that, if the following radial distribution functions consist of either the #1s# or the #2s#, which is which?

HINT: if the radial part of the wave function, #R_(nl)(r)# goes to zero, so does the radial probability density, which is proportional to #R_(nl)^2(r)#.


Graphed from hydrogen atom wave functions