Which phenomenon describes how light interacts with matter and releases energy?

The correct answer is the photoelectric effect, which describes a process where light, specifically photons, interact with matter and cause the ejection of electrons from a material. This phenomenon occurs when light of sufficient energy (typically ultraviolet or higher frequency) strikes a material, typically a metal, and provides enough energy to overcome the binding energy of electrons within that material. When these electrons are released, they can then contribute to electric current in a circuit, which can be harnessed for various applications, such as in solar panels and photo detectors.

Photoconductivity is related to the change in electrical conductivity of a material when exposed to light, but it does not necessarily involve the release of electrons as in the photoelectric effect. Reflection describes how light bounces off surfaces but does not involve energy release from the material. Photon emission refers to the process of a photon being emitted from an atom or a molecule but does not specifically relate to the interaction with light and the consequent release of energy from the material's structure.

Understanding the photoelectric effect is essential in applications like photovoltaic technology, where the conversion of light into usable electrical energy hinges on this fundamental interaction.