What role does a photon play in the photoelectric effect?

The photoelectric effect is a phenomenon where electrons are ejected from a material, typically a metal, when it is exposed to light of sufficient energy. In this context, a photon plays a crucial role as it represents a discrete packet of energy associated with electromagnetic radiation, including visible light.

When a photon strikes the surface of a material, it can transfer its energy to an electron. If the energy of the photon is greater than the work function of the material—essentially the minimum energy needed to remove an electron from the material—the electron is ejected from the surface. This process highlights the interaction between light and matter, demonstrating that light behaves both as a wave and a particle, with photons being the particles in this scenario.

The other options do not accurately describe the role of a photon in the photoelectric effect. Photons do not create energy from light; instead, they carry energy that can be transferred to electrons. They do not change color when interacting with materials in this effect, nor do they serve a role in reflecting light away from the surface when it comes to the ejection of electrons. Thus, the statement that a photon strikes electrons and releases them if it has enough energy encapsulates the essence of the photoelectric effect effectively.