Threshold Frequency: Find Energy of Photoelectron w/ 0.4eV Work Function

In summary, threshold frequency is the minimum frequency of light required to eject an electron from the surface of a metal, unique to each metal and dependent on its work function. It is directly proportional to the energy of a photoelectron, which can be determined using the formula E = hν - Φ. The work function is the minimum amount of energy required to remove an electron from a metal surface, measured in electron volts and determined by the strength of the bond between the electrons and the metal surface. The threshold frequency cannot be changed for a specific metal, but can vary between different metals due to their different work functions.
  • #1
jazzchan
27
0
Dear all

The question is :
A certain material has a work function of 0.4eV. What is the energy of a single photon of electromagnetic radiation at the threshold frequency for liberation of photoelectrons?

Would u give me some hint how to find the threshold frequency at first ??

thanks all

jazz
 
Physics news on Phys.org
  • #2
Hint : Photoelectric Eqn
 
  • #3
can i assume the equation is:
K.E = hf - work function = 0 ??

thanks
 
  • #4
Right. At the threshold frequency the photons have an energy just equal to the work function.
 

1. What is threshold frequency?

Threshold frequency is the minimum frequency of light required to eject an electron from the surface of a metal. It is unique to each metal and is dependent on the work function of the metal.

2. How is threshold frequency related to the energy of a photoelectron?

The energy of a photoelectron is directly proportional to the frequency of the incident light. This means that as the frequency of light increases, the energy of the photoelectron also increases. Therefore, threshold frequency is used to determine the minimum energy required to eject an electron from a metal surface.

3. What is work function?

Work function is the minimum amount of energy required to remove an electron from the surface of a metal. It is measured in electron volts (eV) and is unique to each metal. The work function is determined by the strength of the bond between the electrons and the metal surface.

4. How do you find the energy of a photoelectron with a work function of 0.4eV?

To find the energy of a photoelectron with a work function of 0.4eV, you can use the formula E = hν - Φ, where E is the energy of the photoelectron, h is Planck's constant, ν is the frequency of the incident light, and Φ is the work function. Simply plug in the values and solve for E.

5. Can threshold frequency be changed?

No, the threshold frequency for a specific metal cannot be changed. It is a characteristic property of the metal and is determined by its work function. However, the threshold frequency can vary for different metals, as each metal has a different work function.

Similar threads

  • Introductory Physics Homework Help
2
Replies
35
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
858
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Quantum Physics
Replies
12
Views
667
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
9K
Replies
5
Views
578
  • Introductory Physics Homework Help
Replies
1
Views
4K
  • Introductory Physics Homework Help
Replies
1
Views
884
Replies
4
Views
1K
Back
Top