Understanding the Photoelectric Effect and its Effects on Metal Decay

In summary, the question is focused on understanding why a metal plate maintains its charge when exposed to visible or UV light, as well as how to calculate the number of photons emitted per second when given the wavelength and power of a wave. It is clarified that visible light does not have enough energy to release electrons from the metal and that the photoelectric effect does not cause metal to decay over time.
  • #1
Marshall878
7
0
Im trying to get my head around a question in a book as i thought it would be good to give them ago as I am struggling.

The question is:

Explain why a metal plate does not lose its charge when;

a) the plate is + charged and illuminated with visible light.

b) the plate is - charged and illuminated with UV light

Also, when given wavelength and power of a wave, how do you work out the number of photons emitted per second?
 
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  • #2
a)Even though the plate are being exposed for visible light, the light has not enough energy to free electrons from the metal.

b)The plate has already a negative charge, and won't become positive if you expose it to UV light. The effect releases electrons, its not filling up whit them.
 
  • #3
I have a question about the photoelectric effect. Does it cause metal to decay? It involves emission of electrons from the metal and as far as I know there are no electrons being replaced: does the light cause the metal to break down after a long period of time?
 

Related to Understanding the Photoelectric Effect and its Effects on Metal Decay

1. What is the photoelectric effect?

The photoelectric effect is a phenomenon in which electrons are emitted from a material when it is exposed to light of a certain frequency or higher. This effect was first observed by Heinrich Hertz in 1887 and was later explained by Albert Einstein in 1905.

2. What is the significance of the photoelectric effect?

The photoelectric effect is significant because it provided evidence for the particle nature of light, as proposed by Einstein's theory of photons. It also led to the development of technologies such as solar cells and photomultiplier tubes.

3. How does the photoelectric effect work?

When light of a certain frequency, known as the threshold frequency, is shone on a metal surface, it transfers its energy to the electrons in the metal. If the energy of the light is high enough, it can cause the electrons to be emitted from the metal, creating a flow of electric current.

4. What factors affect the photoelectric effect?

The photoelectric effect is affected by the frequency and intensity of the incident light, as well as the properties of the material being used. Higher intensity and higher frequency light will result in a greater number of electrons being emitted, while certain materials may have a lower threshold frequency and be more sensitive to the effect.

5. How is the photoelectric effect used in modern technology?

The photoelectric effect is used in a variety of technologies, such as solar cells, photomultiplier tubes, and photoelectric sensors. Solar cells use the photoelectric effect to convert light energy into electrical energy, while photomultiplier tubes and sensors use it to detect and measure light levels. It is also used in imaging technologies, such as digital cameras and x-ray machines.

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