A K shell electron is ejected from a tungsten atom

[tlrmaus]

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.

 

[geoelectronics]

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/

 

[DrClaude]

The term characteristic is used because these x-rays are characteristic of the element that emits them. See https://en.wikipedia.org/wiki/Characteristic_X-ray

 

[geoelectronics]

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

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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.​

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[DrClaude]

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.