The photoelectric effect is the phenomenon where certain metals emit electrons when exposed to light or other forms of electromagnetic radiation.
The photoelectric effect was first observed and explained by Albert Einstein in 1905.
Einstein's explanation of the photoelectric effect helped to revolutionize our understanding of light and energy. His work on the photoelectric effect also contributed to the development of quantum mechanics.
The photoelectric effect provides evidence for the dual nature of light, which states that light has both wave-like and particle-like properties. The emission of electrons from metals when exposed to light suggests that light behaves as a stream of particles, known as photons.
The photoelectric effect is used in a variety of applications, including solar panels, photovoltaic cells, and photoelectric sensors. It is also used in photography and in the production of X-rays.