Write a note on characteristic x-ray spectra `:`

Explanation

(i) X-ray spectra show some narrow peaks at some well -defined wavelengths when the target is hit by fast electrons.
(ii) The line spectrum showing these peaks is called characteristic x - ray spectrum. This x-ray spectrum is due to the electronic transitions within the atoms.
(ii) When an energetic electron penetrates into the target atom and removes some of the K-shell electrons.
(iv) Then the electrons from outer orbits jump to fill up the vacancy so created in the K-shell.
(v) During the downward transition, the energy difference between the levels is given out in the form of x-ray photon of definite wavelength.

(vi) Such wavelengths, characteristic of the target, constitute the line spectrum.
(vii) It is evident that K-series of lines in the x-ray spectrum of an element arises due to the electronic transitions from L,M,N,`"...."` levels to the K-level . Similarly, the longer wavelength L-series originates when an L-electron is knocked out of the atom and the corresponding vacancy is filled by the electronic transitions from M,N,O,`"....."` and so on.
(viii) The `K_(alpha)` and `K_(beta)` of the K-series of molybdenum are shown by the two peaks in its x-ray spectrum.