The phenomenon described in the question is known as the photoelectric effect. When the surface of a metal is irradiated with light, electrons can be ejected from the metal. This happens when the energy of the photons in the light is higher than the binding energy that holds the electrons in the metal. The photons transfer their energy to the electrons, causing them to overcome the binding energy and escape from the metal surface.

Option 1: Photoelectric effect - This is the correct answer. It accurately describes the phenomenon of electrons being ejected from a metal surface when irradiated with light.

Option 2: Compton effect - This phenomenon involves the scattering of photons by charged particles, resulting in a change in the wavelength of the photons. It is unrelated to the ejection of electrons from a metal surface.

Option 3: Zeeman effect - This effect refers to the splitting of spectral lines in the presence of a magnetic field. It does not involve the ejection of electrons from a metal surface.

Option 4: Photovoltaic effect - This effect involves the generation of an electric current when certain materials are exposed to light. It is not directly related to the ejection of electrons from a metal surface.

In summary, the correct answer is option 1, the photoelectric effect.