An argon atom has a K_ X-ray wavelength of 0.36 nm . To ionize an argon atom, a minimum energy of 16 eV is required. Determine the energy necessary to knock out an electron from the K shell of an argon atom.

Step-by-step solution

The K_ X-ray is emitted when an electron transitions from the M shell to the K shell. The energy of the emitted K_ photon is given by: E_ K_ = E_M - E_K where E_M and E_K are the energies of the M and K shells, respectively. The energy of the K_ photon can be calculated using the given wavelength = 0.36 nm : E_ K_ = hc = 1242 eV nm 0.36 nm = 3450 eV = 3.45 keV For an argon atom, the outermost electrons are in the M shell ( n=3 ). The ionization energy is the energy required to remove an electron from this outermost