Question

Every metal has a defined work function. Why do all photo-electrons not come out with the law of energy if incident radiation is monochromatic? Why is there an energy distribution of photo-electrons?

Answer 1

As per the question, we will first explain what the work function of metals defines or indicates, by which we can explain why all photo-electrons do not come out with the law of energy if incident radiation is monochromatic. As the minimum or the least energy required for the electron in the highest level of the conduction band to get out of the metal.

Complete answer:
Work function indicates the minimum energy required for the electron in the highest level of the conduction band to get out of the metal. This effect can be attributed to the transfer of energy from light to an electron, according to classical electromagnetic theory. Changes in the kinetic energy of the electrons emitted from the metal would be caused by changes in the intensity of light, according to this theory.

Due to the fact that electrons exist in a continuous band of levels, different electrons require varying amounts of energy to leave the atom. As a result, electrons scattered by monochromatic radiation have various energies. The energy levels of all electrons in an atom are not the same. When a beam with some photon energy strikes a metal surface, electrons emerge from various levels with varying energies.

As a result, the energy distributions of these released electrons differ.The work function shows how much energy it takes for an electron at the highest level of the conduction band to escape from a metal. As a result, electrons thrown off from various levels have different energy when exposed to the same input radiation.

Note: Absorbed light causes electrons to be emitted from matter. The study of the photoelectric effect led to significant advances in our knowledge of the quantum nature of light and electrons, as well as influencing the development of the wave-particle duality notion.