We are asked what did Einstein propose to explain the photoelectric effect
The photoelectric effect is the emission of electrons or other free carriers when light hits a material
What did Einstein propose to explain the photoelectric effect?
a. Metals are very reflective to light.
b. High intensity light is necessary to observe the photoelectric effect.
c. All metals have the same work function.
d. Light energy must come in packets.
e. The kinetic energy of the photoelectrons increases as the light intensity is increased.