1. QUESTION:
Which of the following is not a valid name for an atomic orbital? A. 1s, B. 2s, C. 2d, D. 3p
Principal quantum number (n) is the number that starts the name of the orbital: s s d p n= n= n= n=3
Code letters for orbital quantum number (l): l=0: s. l=1: p l=2: d l=3; f l=4; g
l= l= l= l=1
Rule: l < n
SCRIPT
Which of the following is not a valid name for an atomic orbital? One ess…
Two ess…
Two dee… Or
Three pee…
PAUSE 2 SECONDS
One way to answer this question is to examine the quantum numbers implied by the name of the orbital.
CLICK
The principal quantum number is the number that starts the name of the orbital.
So for the choices given here
CLICK The principal quantum numbers are …
one for one ess…
Two for two ess…
Two for two dee…
And three for three pee
The letters in the name of the orbital are codes for the value of the orbital quantum number ell…The code letters are as follows….
Ess for ell equals zero
Pee for ell equals one
Dee for ell equals two
Eff for ell equals three
And
Gee for ell equals four
Therefore, the orbital quantum number ell for the choices given here are….
Zero for one ess…
Zero fro two ess…
Two for two dee..
And one for three pee
The rule for quantum numbers is that the orbital quantum number ell must be less than the principal quantum number n.
If we examine the choices we have here, we can see that the value of ell is less than en, except in choice C.
Therefore… two dee…
CLICK which would imply quantum numbers of en equals 2 and dee equals two…
Is not a valid name for an atomic orbital.
PAUSE 2 seconds
Another way to determine the answer to this question is to simply remember that
For the first shell….en equals one…. There is only one orbital…. The one ess orbital…
For the second shell…. En equals two…. There are only two kinds of orbitals…. Two ess and two pee….
For the third shell…. En equals three…. There are three kinds of orbitals…. Three ess, three pee, and three dee…
For the fourth shell…. En equals four….. There are four kinds of orbitals…. Four ess, four pee, four dee, and four eff…
And so on….
END RECORDING

2. The orbitals are:
For n=1 (first shell): s (l = 0)
For n=2 (second shell): 2s, 2p (l = 0 and 1)
For n=3 (third shell): s, 3p, 3d (l = 0, 1, and 2)
For n=4 (fourth shell): 4s, 4p, 4d, 4f (l = 0,1,2, and 3)
etc.

3. Video ID: © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Glenn V. Lo Funded by Louisiana Board of Regents Contract No. LA-DL-SELECT-13-07/08