4The photoelectric effect is best explained by treating light as a Particle
5Albert Einstein explained the photo- electric effect in 1905. I was only 26in 1905!!Albert Einstein explained the photo- electric effect in 1905.He won the Nobel Prize for his work in 1921.He also published his special theory of relativity in the same year.
6The Photoelectric effect occurs when light is shown on a metal The Photoelectric effect occurs when light is shown on a metal. The light ejects electrons from the metal producing an electric current..
8According to classical physics, high intensity light would eject electrons with greater kinetic energy. Experimental results contradicted this theory.
9Experiments showed that the kinetic energy of the electrons depended on the frequency of the light. Low frequency light, no matter how intense could not eject a single electron.High frequency light with a very small intensity was able to eject electrons with a large kinetic energy
10Experiments were done to find the relationship between the kinetic energy of the ejected electrons and the frequency of the incident light. They resulted in the following graph:
15Light is a particle, called a photon Light is a particle, called a photon. Each particle has a energy that is directly proportional to the frequency of the light.E = hfE = Energyh = Planck’s Constant (6.63x10-34 Js)f = frequency of the light
16 represents the work function of the metal. It is the minimum energy needed to eject an electron from the metal.
17PRACTICAL APPLICATIONS The Photoelectric Cellvideo cameraselectric eyesburglar alarmsnight lightssolar powervideo games
22Sample QuizThe photoelectric effect is best explained by treating light as a ___________?Who won the Nobel Prize for the explaining the photoelectric effect?List two practical applications of the photo electric effect.