The work function (Φ) of a photoelectricmaterial is the energy that a
photon of light must possess to just expel an electron from thesurface of
the material. The corresponding frequency of the light is thethreshold
frequency (νth) and Φ = h νth. The higher the energy of theincident
radiation, the more kinetic energy that ejected electrons have inmoving
away from the surface. The work function for cesium is 3.42 X10-19J.
1. What is the threshold frequency for the photoelectric effectfor
cesium.
2. Will 1000 nm infrared radiation produce the photoelectric effecton
cesium? Explain and show calculations.
3. A 425-nm blue light shines on a piece of cesium. Will thisradiation
produce a photoelectric effect? Show calculations as in B.
Lecture : Gen Chem Lecture-8
Document Summary
Radiation- electric and magnetic fields propagate as waves through empty space or through a medium: a wave transmits energy. The photoelectric effect: when light strikes the certain metal surface electron are ejected electron emission only occurs when the incident light frequency exceed certain threshold value, v>vo threshold frequency. Particle like which is called photon. (by plank) In part cle model photon hit metal w th hv energy, if hv is greater than the b ng ng energy of the electron (wh ch s called work funct on) photoelectrons ejected.