The Kα and Kβ X -rays of molybdenum have wavelengths 0.71 A∘ and 0.63 A∘ respectively. Find the wavelength of Lα X-ray of molybdenum.
Kα=EK−EL ...(1)
λKα=0.71A∘
λKβ=0.63A∘
Kβ=EK−EM ...(2)
Lα=EL−EM ...(3)
Substracting (2) from (1)
Kα−Kβ=EM−EL=−Lα
or Lα=Kβ−Kα
= 3×1080.63×10−10−3×1080.71×10−10
= 4.761×1018−4.225×1018
= 0.526×1018 Hz
Again λ=3×1080.536×1018
= 5.6×10−10=5.6A∘