Exploring Electron Transitions - Why 2p and 2d Lines?

In summary, the question being discussed is about the emission spectrum of x-rays and why there are only 2p and 2d lines shown instead of 3p and 5d lines. DrDu explains that the transitions from different shells have different rates, with the 2p-1s transition being the most likely. They also mention that the 3p and 5d orbitals are energetically degenerate and split into two groups due to spin-orbit interaction. This results in different term components, which are labeled as K, L, M, etc. Thank you to DrDu and Bob S for providing helpful explanations.
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mccoy1
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Hi guys, I don't know if this question has been asked before, but I searched the forum but didn't get answer to my question. I was looking at the transition when a core electron is knocked off by energy and that an upper level electron replaces it and x ray is released. Question, why are there 2p lines (instead of 3) and 2d lines (instead of 5 orbitals)?
I'd appreciate your input.
Thanks
 
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  • #2
bump...46 views and no a single reply?:)
 
  • #3
Maybe people are having a hard time understanding your question. Can you include a figure of the emission spectrum are rewrite your question in the context of the figure?
 
  • #4
Gokul43201 said:
Maybe people are having a hard time understanding your question. Can you include a figure of the emission spectrum are rewrite your question in the context of the figure?

oh okay. First of all, thanks for the reply. I don't have a diagram here because I'm using a mobile phone. I was talking about x-rays energy diagram. Usually they have K, L, M etc shell. Take M shell for example. The lines shown are one 3s, two 3p, two 3d. So what i don't get is the fact that only 2 p-energy levels are drawn instead of 3(because p has 3 subshell, not two. Same for d, only 2 likes instead of 5. Thanks
 
  • #5
This might help.
Suppose a core electron (in the 1s shell) is knocked out by deep core photoejection. The only allowed atomic electron transitions to fill the empty 1s state are δl = 1 transitions, i.e., from 2p, 3p, 4p, etc.

In looking at the transition rates (inverse lifetimes) for 2p-1s, 3p-1s, 4p-1s, etc. in the single-electron hydrogen atom, they are 6.25 x 108, 1.64 x 108, 0.68 x 108 sec-1 respectively, implying that the 2p-1s transition is the most likely.

Bob S
 
  • #6
Keep also in mind that the 3 p orbitals or the 5 d orbitals are energetically degenerate in zeroth order. They may split into two groups (term components) due to spin-orbit interaction. There is only one term [tex]^3S_{1/2}[/tex] for the primary hole formed in the K shell. While for a hole in a p or d subshell there are two possibilities, [tex]^2P_{1/2} [/tex] and [tex]^2P_{3/2} [/tex] for a hole in the p-shell and [tex]^2D_{3/2} [/tex] and [tex]^2D_{5/2}[/tex] in the d-shell, respectively. This is due to the two possibilities to combine spin with the orbital angular momentum, i.e., J=L+S and J=L-S.
 
  • #7
DrDu said:
Keep also in mind that the 3 p orbitals or the 5 d orbitals are energetically degenerate in zeroth order. They may split into two groups (term components) due to spin-orbit interaction. There is only one term [tex]^3S_{1/2}[/tex] for the primary hole formed in the K shell. While for a hole in a p or d subshell there are two possibilities, [tex]^2P_{1/2} [/tex] and [tex]^2P_{3/2} [/tex] for a hole in the p-shell and [tex]^2D_{3/2} [/tex] and [tex]^2D_{5/2}[/tex] in the d-shell, respectively. This is due to the two possibilities to combine spin with the orbital angular momentum, i.e., J=L+S and J=L-S.


Thank you very much DrDu..You hit the nail on the head. I didn't know that those states arise from the microstates because they just label them K, L, M, L which is not very informative.
Thank you too Bob S.
 

FAQ: Exploring Electron Transitions - Why 2p and 2d Lines?

1. What are electron transitions?

Electron transitions refer to the movement of electrons between different energy levels in an atom. This movement can be caused by the absorption or emission of energy in the form of light or heat.

2. Why are 2p and 2d lines important in electron transitions?

2p and 2d lines are important because they represent the energy levels of electrons in the second shell of an atom. These lines are associated with specific transitions between energy levels, which can help scientists identify the elements present in a sample.

3. How are 2p and 2d lines observed?

2p and 2d lines can be observed using spectroscopy techniques, such as emission or absorption spectroscopy. These techniques involve passing light through a sample and analyzing the wavelengths of light that are absorbed or emitted by the electrons in the sample.

4. What causes 2p and 2d lines to appear in different colors?

The specific colors observed in 2p and 2d lines are determined by the energy difference between the electron's initial and final energy levels. This energy difference corresponds to a specific wavelength of light, which is then perceived as a specific color by our eyes.

5. How do scientists use 2p and 2d lines in their research?

Scientists use 2p and 2d lines to identify the elements present in a sample and to study the electronic structure of atoms. By analyzing the wavelengths of light emitted or absorbed by the electrons, scientists can gain insight into the arrangement of electrons in different energy levels and the chemical composition of a sample.

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