Trying to understand a reading on Moseley and the X-ray Spectra

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SUMMARY

The discussion centers on Henry Moseley's choice to plot \(\sqrt{f}\) versus atomic number \(Z\) instead of \(f\) versus \(Z\), which results in a linear graph, as opposed to an exponential relationship. The K series describes transitions to vacancies in the n=1 shell, while the L series pertains to n=2 vacancies, with K series X-rays exhibiting higher frequencies and energy. The values \(b=7.4\) for the L series and \(b=1\) for the K series reflect the shielding effects of electrons. Additionally, gaps in Moseley's experiment, particularly regarding argon at \(Z=18\), are linked to Auger's contributions involving copper and aluminum in the context of electron transitions.

PREREQUISITES
  • Understanding of Moseley's Law and its implications in X-ray spectroscopy.
  • Familiarity with atomic structure, specifically K and L shells.
  • Knowledge of quantum mechanics, particularly principal quantum numbers.
  • Basic principles of X-ray production and photon energy relationships.
NEXT STEPS
  • Study Moseley's Law in detail, focusing on the mathematical derivation and implications.
  • Explore the significance of K and L series in X-ray spectroscopy.
  • Investigate Auger electron spectroscopy and its applications in material science.
  • Learn about the shielding effect in multi-electron atoms and its impact on atomic transitions.
USEFUL FOR

Students and professionals in physics, particularly those specializing in atomic physics, spectroscopy, and materials science, will benefit from this discussion.

UrbanXrisis
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I was wondering why Henry Moseley ploted \sqrt{f} vs. Z instead of just f vs. Z. I'm guessing it is because this way, the graph of \sqrt{f} vs. Z would be linear? But if it was just f vs. Z, wouldn't the equation just be exponential?

Also, what is the significance of the L seriese and the K seriese? The K seriese describes the atomic transitions to vacancies in the n=1 shell where the L seriese describes the transition to the n=2 vacancy right? So by Moseley's plot, i see that there is a lower frequency for the K-seriese which means that more energy is released right? But what I really don't understand is why b=7.4 for the L seriese and b=1 for the K seriese. This is something my book does not explain. and why (Z-b)?

why where there gaps in Moseley's experiment such that argon fell into Z=18? and I don't understand what exactly Auger did to help this out. All i got out of the book was that there is a third electon? I think the elements that Auger used were Cu and Al to help out Moseley's expirments?
 
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UrbanXrisis said:
I was wondering why Henry Moseley ploted \sqrt{f} vs. Z instead of just f vs. Z. I'm guessing it is because this way, the graph of \sqrt{f} vs. Z would be linear? But if it was just f vs. Z, wouldn't the equation just be exponential?

Also, what is the significance of the L seriese and the K seriese? The K seriese describes the atomic transitions to vacancies in the n=1 shell where the L seriese describes the transition to the n=2 vacancy right? So by Moseley's plot, i see that there is a lower frequency for the K-seriese which means that more energy is released right? But what I really don't understand is why b=7.4 for the L seriese and b=1 for the K seriese. This is something my book does not explain. and why (Z-b)?

why where there gaps in Moseley's experiment such that argon fell into Z=18? and I don't understand what exactly Auger did to help this out. All i got out of the book was that there is a third electon? I think the elements that Auger used were Cu and Al to help out Moseley's expirments?
Quick response to the first question. The frequency of the X-ray (or photon in general) is proportional to Z2 in the hydrogen atom, or for K electrons. The significance of the K and L shells (principal quantum numbers, n = 1 and 2, respectively) have to do with the energies of the transitions to those orbits. K series X-rays should have higher frequency/shorter wavelength than L-series X-rays.

The K electrons are in the first shell and thus exposed to the full nuclear charge. The L electrons are shielded by the K electrons and partially by other L-electrons, hence the correction on Z.

More later.
 

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