The L →K transition of an X-ray tube containing a molybdenum (Z = 42) target occurs at a wavelength of 0.0724 nm. Use this information to estimate the screening parameter of the K-shell electrons in molybdenum.
The wavelength λL K = 0.0724 nm corresponds to the energy
Eγ = 1,241/λL K = 1,241/0.0724 = 17,141 eV
Now 17,141 = 13.6 × 3/4(Z − σ)2
The factor 3/4 is due to the L → K transition.
Substituting Z = 42, and solving for σ we obtain σ = 1.0
