Questions on light and photoelectric effect

In summary: Each line corresponds to a single energy level, with the Lyman series (named after George Lyman) generated by electrons dropping to the 5th lowest energy level.
  • #1
esvion
19
0
1. When a certain metal reflects a certain frequency of light, it will kock loose electrons and emit them. Where exactly do these electrons come from? If a metal emits electrons, doesn't that metal eventually gain a positive charge of some sort? Is it possible for piece of metal to lise all of its electrons through the photoelectric effect?


2. Similar to the question above: when electricity is passing through a power cable, does the copper in that cable lose their electrons or just carry them from another source?

3. Question on line emission spectrum: does each line in a spectrum represent an electron releasing a photon from a specific energy level? How can one hydrogen atom release an entire series of lines (i.e. Lyman series) if it only has one electron to emit energy for one specific line? The Lyman series of lines has electrons dropping to ground-states from five different energy levels.

Thanks!
 
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  • #2
esvion said:
1. When a certain metal reflects a certain frequency of light, it will kock loose electrons and emit them. Where exactly do these electrons come from? If a metal emits electrons, doesn't that metal eventually gain a positive charge of some sort? Is it possible for piece of metal to lise all of its electrons through the photoelectric effect?


2. Similar to the question above: when electricity is passing through a power cable, does the copper in that cable lose their electrons or just carry them from another source?

In both cases, the metal/cathode are grounded.

3. Question on line emission spectrum: does each line in a spectrum represent an electron releasing a photon from a specific energy level? How can one hydrogen atom release an entire series of lines (i.e. Lyman series) if it only has one electron to emit energy for one specific line? The Lyman series of lines has electrons dropping to ground-states from five different energy levels.

Thanks!

A hydrogen gas that you normally use in discharge tubes consists of many hydrogen atoms/molecules, not just one. When you supply energy to them, they all have a distribution of energy that they have absorbed, and thus, can release. You are not looking at just one hydrogen atom.

Zz.
 
  • #3
ZapperZ said:
In both cases, the metal/cathode are grounded.

I am not familiar with that term. You mean they have connections into the earth?
 
  • #4
Yes. English-speaking people on the eastern side of the Atlantic say "earthed." People on the western side say "grounded."
 
  • #5
Not really, I'm from the eastern side and I learned it as "grounded".
 
  • #6
esvion said:
1. When a certain metal reflects a certain frequency of light, it will kock loose electrons and emit them. Where exactly do these electrons come from? If a metal emits electrons, doesn't that metal eventually gain a positive charge of some sort? Is it possible for piece of metal to lise all of its electrons through the photoelectric effect?

<snip>

The electrons (initially) come from the conduction band of the metal- they are essentially electrons that are free to move anywhere they want to.As the conduction band is depleted, the energy required to remove additional electrons increases, meaning the illumination wavelength must decrease. It's possible to remove tightly bound electrons from atoms with x-rays, so I'd imagine that if you tried, you could indeed strip out all the conduction electrons and many of the valence electrons by the photoelectric effect. At some point, you could not supply enough energy to remove an additional electron.


esvion said:
3. Question on line emission spectrum: does each line in a spectrum represent an electron releasing a photon from a specific energy level? How can one hydrogen atom release an entire series of lines (i.e. Lyman series) if it only has one electron to emit energy for one specific line? The Lyman series of lines has electrons dropping to ground-states from five different energy levels.

Thanks!

Yes- and the series is generated by using different wavelengths of excitation illumination- this moves electrons to different excited states, allowing for the emission lines to appear.
 

What is light?

Light is a form of electromagnetic radiation that is visible to the human eye. It is made up of particles called photons, which have both wave-like and particle-like properties.

How does light interact with matter?

Light can interact with matter in several ways, including absorption, reflection, refraction, and scattering. The way in which light interacts with matter depends on the properties of both the light and the matter.

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. This effect was first observed and explained by Albert Einstein and is a fundamental concept in quantum mechanics.

What is the relationship between light frequency and the photoelectric effect?

The photoelectric effect is directly related to the frequency of light. The higher the frequency of light, the greater the energy of the photons, and the more likely they are to cause the emission of electrons from a material.

What are some practical applications of the photoelectric effect?

The photoelectric effect has many practical applications, including solar cells, photodetectors, and digital cameras. It is also used in medical imaging and various types of sensors, such as motion detectors and smoke detectors.

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