Question

What did Einstein say about the photoelectric effect?

Answer 1

When electromagnetic radiation, such as light, strikes a substance, it causes electrons to be emitted. Photoelectrons are electrons that are emitted in this way. To draw conclusions about the characteristics of atoms, molecules, and solids, the phenomena is investigated in condensed matter physics, solid state chemistry, and quantum chemistry. The effect is used in electrical systems that are designed to detect light and emit electrons at specific times.

Complete answer:
While classical electromagnetism appears to suggest that continuous waves of light are responsible for the transfer of energy to photoelectrons, the theory proposed by German physicist Albert Einstein to explain this phenomenon considers light to be made up of millions of ‘packets' that behave like particles. Photons are the units of measurement for these light "packets." The experimental results connected with the photoelectric effect are well known to violate conventional electrodynamics' assumptions (a field of theoretical physics that deals with the study of the interactions between charges and electric currents with regards to the Newtonian model).
Albert Einstein proposed a hypothesis describing the photoelectric effect in 1905, based on an idea initially proposed by German theoretical physicist Max Planck, who proposed that light is made up of tiny packets of energy known as photons. The energy carried by each packet of light is equal to hv, where h stands for Planck's constant and v stands for the incident light's frequency.

Note:
Because light is packaged into photons, Einstein hypothesised that when a photon collides with a metal's surface, the full photon's energy is transmitted to the electron. A portion of this energy is utilised to free the electron from the grip of the metal atom, with the remainder going to the expelled electron as kinetic energy. During the impact, electrons released from under the metal surface lose some kinetic energy. Surface electrons, on the other hand, carry all of the proton's kinetic energy and have the highest kinetic energy.