Spectroscopic Notation Problem

In summary, the quantum numbers for the states described in spectroscopic notation are 2S3/2 l = 0, s = 1/2, j = 3/2; 3D2 l = 2, s = 1, j = 2; and 5P3 l = 1, s = 2, j = 3. The first state, 2S3/2, is impossible due to the rule that when L = 0, J = S. The maximum value of J is L+S, the minimum value of J is |L-S|, and J takes all values in between in steps of 1. For the second and third states, j can
  • #1
njdevils45
Moved from a technical forum, so homework template missing
Question

(a) Write down the quantum numbers for the states described in spectroscopic notation as 2S3/2, 3D2 and 5P3.
(b) Determine if any of these states are impossible, and if so, explain why. (Please note that these could describe states with more than one electron.)

My Attempt

A)

I came up with the quantum numbers for everything that I'm pretty sure is correct. Was hoping I could get a double check on this.
2S3/2 l = 0, s = 1/2, j = 3/2
3D2 l = 2, s = 1, j = 2
5P3 l = 1, s = 2, j = 3

B)
I'm almost 100% confident that 2S3/2 is impossible because when l = 0, j must = 1/2.

I'm not sure about the other two because I don't know all the rules for what s can be compared to l and j.

Any help would be greatly appreciated. Thank you!
 
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  • #2
njdevils45 said:
I'm almost 100% confident that 2S3/2 is impossible because when l = 0, j must = 1/2.
Not exactly. When ##L=0##, ##J=S##.

njdevils45 said:
I'm not sure about the other two because I don't know all the rules for what s can be compared to l and j.
What are the rules of addition of angular momenta? In other words, given ##L## and ##S##, what are the possible values of ##J=L+S##?
 
  • #3
(A) is correct
You are correct that 2S3/2 is impossible.

The rule is that the maximum value of J is L+S, the minimum value of J is |L-S| and J takes all values in between in steps of 1.
 
  • #4
DrClaude said:
Not exactly. When ##L=0##, ##J=S##.

So to say that when l = 0, j must = 1/2 for the first state is correct right?

DrClaude said:
What are the rules of addition of angular momenta? In other words, given ##L## and ##S##, what are the possible values of ##J=L+S##?

Does this mean that j could only equal 1,2, or 3 for the second and third one? Therefore the value for j is possible for those two?
Is the value for s possible for the other two though? Is s allowed to be integer? I know for a fact that the values for l is possible for all three of them, and assuming that s is correct, the value for j is possible for the 2nd and third state, but are the values of s possible for the 2nd and third state?
 
  • #5
kuruman said:
(A) is correct
You are correct that 2S3/2 is impossible.

The rule is that the maximum value of J is L+S, the minimum value of J is |L-S| and J takes all values in between in steps of 1.

So for the second and third states, j is correct assuming the value for s is correct? In that case is the value for s possible for those two states?
 
  • #6
njdevils45 said:
So to say that when l = 0, j must = 1/2 for the first state is correct right?
Correct.

njdevils45 said:
Does this mean that j could only equal 1,2, or 3 for the second and third one? Therefore the value for j is possible for those two?
Yes on both.

njdevils45 said:
Is the value for s possible for the other two though? Is s allowed to be integer? I know for a fact that the values for l is possible for all three of them, and assuming that s is correct, the value for j is possible for the 2nd and third state, but are the values of s possible for the 2nd and third state?
The spectroscopic notation is based on ##S##, the total spin of the electrons. It can have a half-integer or an integer value.
 
  • #7
DrClaude said:
The spectroscopic notation is based on ##S##, the total spin of the electrons. It can have a half-integer or an integer value.

So in that case the 2nd and third states for the problem are both definitely possible?
 
  • #8
njdevils45 said:
So in that case the 2nd and third states for the problem are both definitely possible?
Yes.
 
  • #9
DrClaude said:
Yes.
Thank you!
 

1) What is spectroscopic notation?

Spectroscopic notation is a system of symbols and numbers used to represent the energy levels and electron configurations of atoms and molecules.

2) How is spectroscopic notation written?

Spectroscopic notation consists of the energy level (n), the subshell (s, p, d, f), and the number of electrons in that subshell. For example, 3p4 represents an energy level of n=3, a p subshell, and 4 electrons in that subshell.

3) Why is spectroscopic notation important?

Spectroscopic notation is important because it allows scientists to easily communicate and understand the energy levels and electron configurations of atoms and molecules. It also helps in predicting the chemical and physical properties of elements and compounds.

4) How do you determine the number of electrons in a subshell using spectroscopic notation?

The number of electrons in a subshell can be determined by the superscript number after the subshell symbol. For example, 3p4 means there are 4 electrons in the p subshell of the third energy level.

5) Can spectroscopic notation be used for all elements?

Yes, spectroscopic notation can be used for all elements in the periodic table. However, it is most commonly used for elements with multiple energy levels and subshells, such as transition metals.

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