A K shell electron is ejected from a tungsten atom

Click For Summary

Discussion Overview

The discussion revolves around a homework problem involving the ejection of a K shell electron from a tungsten atom and the subsequent emission of characteristic x-rays. Participants explore the energies associated with electron transitions between atomic shells and the definition of characteristic radiation.

Discussion Character

  • Homework-related
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Participants discuss the binding energies of the K and L shells in tungsten, noting that the K shell has a binding energy of 69.5 keV and the L shell has a binding energy of 10.5 keV.
  • One participant corrects a terminology error, stating that "characteristic x-ray proton" should be "characteristic x-ray photon."
  • Another participant explains that characteristic x-rays are specific to the element emitting them, linking the term "characteristic" to the unique energies of the x-rays produced by tungsten.
  • A participant calculates the energy of the characteristic x-ray emitted when an electron from the L shell fills the K shell vacancy, arriving at a value of 59.318 keV based on the binding energies provided.
  • There is mention of the binding energies of the L subshells, providing additional detail on the energy levels involved.

Areas of Agreement / Disagreement

Participants generally agree on the definitions and calculations related to the binding energies and the nature of characteristic radiation. However, there are corrections and clarifications made regarding terminology and specific energy values, indicating some level of contention or refinement in the details presented.

Contextual Notes

Some participants provide additional details about the binding energies of the L subshells, which may not have been necessary for the original problem. There is also a correction regarding terminology that highlights the importance of precise language in scientific discussions.

Who May Find This Useful

This discussion may be useful for students studying atomic physics, particularly those interested in x-ray production and the behavior of electrons in atomic shells.

tlrmaus
Messages
8
Reaction score
0

Homework Statement


A K shell electron is ejected from a tungsten atom. The result of this is the emission of a characteristic x-ray proton. (The binding energy of the K shell in tungsten is 69.5keV. The binding energy of the L shell in a tungsten atoms is 10.5 keV).
a) If the vacancy in the K shell is filled by an electron from the L shell, what will the energy of the characteristic x-ray be?
b)If the K shell vacancy was filled by an electron from the M shell, would the enregy by higher or lower than the enregy from part a?
c)Why is this type of radiation called characteristic radiation?


Homework Equations





The Attempt at a Solution


I got part a and b but can't get part c.
 
Physics news on Phys.org
Q: "Homework Statement A K shell electron is ejected from a tungsten atom. The result of this is the emission of a characteristic x-ray proton. (The binding energy of the K shell in tungsten is 69.5keV. The binding energy of the L shell in a tungsten atoms is 10.5 keV)."

A:
1) "characteristic x-ray proton" should say X-Ray PHOTON. In other words and X-Ray photon.
Reference: https://www.physicsforums.com/threads/a-k-shell-electron-is-ejected-from-a-tungsten-atom.482822/

Reference: https://www.physicsforums.com/threads/a-k-shell-electron-is-ejected-from-a-tungsten-atom.482822/
 
2) "(The binding energy of the K shell in tungsten is 69.5keV. The binding energy of the L shell in a tungsten atoms is 10.5 keV)."

This statement should say: element W K-shell binding energy is 69.5250keV.
Element W L-shell has 3 subshells, their binding energies are: L1is12.100keV, L2 is 11.544keV, L3 is 10.207V.

3) "If the vacancy in the K shell is filled by an electron from the L shell, what will the energy of the characteristic x-ray be?"

A: Their emission energy is simply the subtraction of the difference between the vacant K-shall binding energy and the donor electron's kinetic energy, therefore:

Ka1 Characteristic XRF X-Ray: (K) 69.5250keV - (L3) 10.207keV = 59.318keV

So, the unique X-Ray photons released by a K-Shell electron leaving its shell, creating a vacancy there, which is then filled by a donor electron in the element W, and only the element W is 59.318keV.

Being unique to this atom alone, it is a "characteristic" of all isotopes of the tungsten atom.

George Dowell

K 1s
L12s
L22p1/2
L32p3/2
M13s
M23p1/2
M33p3/2
M43d3/2
M53d5/2
69,525.
12,100.
11,544.
10,207.
2,820.
2,575.
2,281.
1,872.
1,809.

 
Last edited:
This homework problem is from 11 years ago. There is now enough information in the thread to help someone with a similar problem. Time to close.
 

Similar threads

  • · Replies 17 ·
Replies
17
Views
4K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
7K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 15 ·
Replies
15
Views
3K