What is Moseley known for?



The Moseley's law (after Henry Moseley) describes the location of the so-called Kα-Lines in the X-ray spectrum (this is the line that corresponds to the transition of an electron from the L-shell to the K-shell).

In a more general form one can also use this law to determine the wavelengths of the other lines of the X-ray spectrum. The wavelength λ of the characteristic X-ray radiation emitted or absorbed during the electron transfer depends on the atomic numberZ of the respective element and thus characteristic of a certain element.

The following applies:


Where:

  • λ - wavelength of the emitted or absorbed X-ray radiation
  • - Wave number of the emitted or absorbed X-ray radiation
  • - Rydberg's constant (1.0973731534 107 m-1)
  • Z - atomic number of the element
  • K - shielding constant (shielding of the nuclear charge by electrons located between the nucleus and the electron in question)
  • n1, n2 - Principal quantum numbers of the two states (n1 = inner shell, n2 = outer shell)

For the transition of an electron from the second (L-shell) to the first shell (K-shell), the so-called Kα-Transition, applies and the corresponding wavenumber is then:

.
The following applies to the transition of an electron from the third (M-shell) to the second shell (L-transition) .

Category: atomic physics