Answer
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Work Step by Step
See Example 28-7, which illustrates how the Bohr model can be used to calculate the wavelengths of x-rays corresponding to electron transitions.
In that example, for an electron dropping from n = 2 down to n = 1 in molybdenum (Z=42), we estimated the nuclear charge seen by the transitioning electron as Z-1 = 42. This was based on the assumption that the electron already in the n = 1 ground state was partly shielding the nuclear charge from the transitioning electron.
Clearly, this is a rough model of the actual process, so we do not expect perfect agreement between our calculated wavelengths, and the experimentally measured wavelengths. We are also neglecting other factors such the recoil of the nucleus due to momentum conservation, which would have to be incorporated into a more complex and accurate model.