The Kα X-ray emission line of tungsten occurs at λ = 0.021 nm. The energy difference between K and L levels in this atom is about
(a) 0.51 MeV
(b) 1.2 MeV
(c) 59 keV
(d) 13.6 eV
Correct Answer is: (c) 59 keV
EK - EL = 1242 eV nm/0.021nm = 124.2/2.1 x 103 eV = 59 ke V.
