The Kβ X -ray of argon has a wavelength of 0.36 nm. The minimum energy needed to ionize an argon atom is 16 eV. Find the energy needed to knock out an electron from the K shell of an argon atom.
Given λ = 0.36 nm
E = 12420.36 = 3450 eV
Energy needed to ionize an argon atom
= 16 eV
Energy needed to knock out an electron from K - shell
= (3450+16)eV
= 3466 eV = 3.466 KeV