SAT Subject Physics Practice Question 479: Answer and Explanation
10. A photovoltaic metal absorbs a photon of yellow light and immediately emits an ultraviolet photon. This is called
E. This is not possible.
Correct Answer: E
The correct answer is (E). The photon of yellow light does not contain enough energy to cause the metal to emit an ultraviolet photon. Remember the energy of a photon is directly related to the frequency of the electromagnetic radiation. The higher the frequency, the higher the energy of the photon of the radiation. Ultraviolet light has a much higher frequency than yellow light, thus its photon is more energetic.