Can you please explain the significance of photoelectric effect?

The photoelectric effect is the emission/removal of electrons, normally, from the surface of a metal. This is done as light is shone on the metal. This is a very useful proof that light can act as a particle, due to the fact that there is a threshold frequency, above which the photoelectric effect only works. The threshold frequency is the lowest frequency at which enough energy(known as the work function) is provided to the electron so that it can be removed from the surface of the metal. This proves that light behaves as a particle as it is evidence that the interaction between the photons of light and the electrons is one to one. Otherwise, if light could only behave as a wave, the photoelectric effect would occur regardless of the frequency of the light, and only have different time delays. 

KA

Related Physics A Level answers

All answers ▸

In an electric propulsion system, alpha particles are accelerated through a potential difference of 100kV at an average rate of 10^20 alpha particles per second. Calculate the average thrust the system can provide.


Describe and explain the life cycle of a star?


A diver of mass 60kg stands on the end of a diving board of length 2m from the pivot point. Calculate the upward force exerted on the retaining spring 30cm from the pivot point.


Newton's Law of Gravitation states: F=GMm/r^2, where G is the gravitational constant (6.67×10−11m^3kg^−1s^−2). Kepler's Third Law, states t^2=kR^3. The mass of the sun is 1.99x10^30kg. Find the value of k and its units