In the photoelectric effect, the work function is the minimum energy required for an electron to escape from the surface of a material.
- Every material has a different work function, depending on how tightly its electrons are bound.
- If incoming light (photons) has energy less than the work function, no electrons are emitted, no matter how intense the light is.
- If the photon’s energy is equal to or greater than the work function, electrons can be emitted, and any extra energy becomes the electron’s kinetic energy.
Key idea: The work function sets the threshold for electron emission. It explains why some materials require higher-frequency light to release electrons.