Question

Quantum transitions that result in the characteristic sharp lines of the X-ray spectrum always involve (A) the inner electron shells (B) electron energy levels that have the same principal quantum number (C) emission of beta particles from the nucleus (D) neutrons within the nucleus (E) protons within the nucleus

Answer 1

(a) the inner electron shells

The characteristic x-ray spectrum is produced as a result of deep collisions. When this happens, an electron is knocked out of a very inner shell and this creates a "hole". To fill this "hole" a higher energy electron will have to drop down to fill this hole. Since that electron will most likely come from the outer more shell, the delta E of this energy level difference is really large. In fact, the delta E is proportional to the emission of a photon within the x-ray size.

E = hc/lambda