He theorized that light carries a different amount of energy based on its frequency, and that this energy is quantized in particles called photons. The threshold frequency is the frequency of light that carries enough energy to dislodge an electron from an atom.
This energy is entirely consumed in the process see References 5. Therefore, the electron gets no kinetic energy at the threshold frequency and it is not released from the atom.
Instead, light must have slightly more energy than that which is present at the threshold frequency in order to give an electron kinetic energy. The work function is a way of describing the amount of energy given to an electron at the threshold frequency. The work function equals the threshold frequency times Planck's constant.
Planck's constant is the proportionality constant that relates a photon's frequency to its energy. Therefore, the constant is required to convert between the two quantities. Planck's constant is equal to about 4. The units of the work function are electron volts. One electron volt is the energy needed to move an electron across a potential difference of one volt. Different metals have characteristic work functions, and therefore characteristic threshold frequencies. For example, aluminum has a work function of 4.
Some materials have a series of different work functions. Ans: The threshold frequency is 1. The threshold frequency for photoelectric emission of electrons from platinum is 1. At zero stopping potential the frequency of incident radiation is more to metal A. Both the metals have the same stopping potential at different frequencies and this frequency is more than metal A.
So, metal A has a higher threshold frequency. Thus, metal A has high threshold frequency. The energy and frequency of a photon are related by: The minimum energy required to produce photo-emission of electrons is called the work function this depends on the type of metal used.
The minimum frequency of light required to give the work function energy is called the threshold frequency. Much less commonly, the photon can be symbolized by hf, where its frequency is denoted by f. No, we cannot make photons travel at any value other than the speed of light. A way to think of it is like, because photons have zero rest mass that is why they can travel at the only other speed available that is less than the speed of light, that is: light speed.
Begin typing your search term above and press enter to search. Sai Charan. Sai Charan Sai Charan 37 1 1 silver badge 4 4 bronze badges. They have different chemical properties. Add a comment. Active Oldest Votes. The value of photocurrent depends on the intensity of the falling radiation. Check out these links : Are number of photons in an incident radiation proportional to its intensity? Improve this answer. Mitchell Mitchell 4, 4 4 gold badges 20 20 silver badges 37 37 bronze badges.
Featured on Meta. Now live: A fully responsive profile. Linked 3.
0コメント