Final answer:
Photon energy is directly related to the applied kilovoltage, with a potential of 50.0 kV generating 50.0 keV electrons, subsequently producing photons with up to 50 keV of energy.
Step-by-step explanation:
The photon energy is closely associated with the applied kilovoltage (kV) in devices like X-ray tubes. When you accelerate an electron, which carries an elementary charge, through an electric potential expressed in volts, the electron achieves an energy measured in electron volts (eV) with a numerical value equivalent to the voltage in volts. Hence, a potential of 50.0 kV will generate electrons with 50.0 keV of energy that can create photons with up to 50 keV of photon energy. This relationship becomes important when considering the penetrating power of the X-rays produced, which can be adjusted based on the kilovoltage setting of the X-ray tube.