Answer:
Photons of light from source X carry more energy than photons of light from source Y
Step-by-step explanation:
According to Einstein's photoelectric equation, the kinetic energy of the emitted photoelectron depends on the energy of the incident photon and the work function of the metal.
For photoelectrons to be ejected from a metal surface, the energy of incident photon must be greater than the work function of the metal. If not, no electron is ejected.
The energy of photon X must be greater than the work function of the metal while the energy of photon Y is less than the work function of the metal. This brings us to the conclusion that the energy of photon X must be greater than that of photon Y.