Answer:
Particle
Explanation:
To understand photoelectric effect the physicists has to view light as a particle and not wave. The wave nature of the light could not explain the phenomenon of photoelectric effect.
Photoelectric effect is emission of electrons from a material when electromagnetic radiation(Light) is incident on it. These emitted electrons are called photoelectrons.
The explain this effect Einstein proposed that beam of light is can not be a wave propagating through space, but a swarm of discrete energy packets, called as photons.
