# Tagged Questions

The observed behavior in which light falling on certain metals can eject electrons from the surface.

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### Extraction efficiency in photoeffect

I am looking at the extraction efficiency of the photoeffect (how many electrons end up in vacuum per photon). I have read in this forum that 1e-5 or less electrons make it outside of metal. Reason is ...
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### Does laser light with less than the work function still ionise some atoms?

If a gas is illuminated with a laser of a frequency less than (but more than half of) the work function of the atoms in the gas, the atoms will be excited into Rydberg atoms. Is there a finite chance ...
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### Photoelectric effect

Why the photoelectric effect is observed only for metals and not for non-metals? Isn't it possible for the photon to release an electron from a non-metal surface?
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### Kinetic energy of an electron with de Broglie wavelength $\lambda$

If an electron has de Broglie wavelength $\lambda$, can I write it's kinetic energy $E = \frac{hc}{\lambda}$? If not then what energy does the equation represent and when can the equation be used ?
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### Photoelectric Effect Changing The Charge of a Metal?

So the photoelectric effect causes metals to emit electrons in contact with light. I have two questions... 1) Does this keep happening until no more electrons are being emitted? 2) Can't this effect ...
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### Why doesn't photoelectric current increase with frequency of the incident wave?

If the frequency of the incident wave is increased, then the kinetic energy of the photoelectrons increases. If so, why doesn't the photoelectric current increase? If the kinetic energy of electrons ...
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### Compton effect in photo-electric?

In photo-electric effect Einstein said that photons incidents on material and gives their energy which will gives kinetic energy to electrons. But i also want to know that why Compton's effect not ...
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### Is there a relationship between kinetic energy of emitted electron and photoelectric current?

I know that photoelectric current is dependent upon intensity of incident light. But it should also be dependent upon kinetic energy of emitted electron because mathematically $I=Q/T$. So if kinetic ...
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### Why doesn't saturation photocurrent depend on frequency of incident ray, keeping intensity constant?

We know that intensity I = nhf, where n is no. of photons striking metal surface per second per unit sq unit area, and f is frequency of incident ray. In the book it was said that if we change the ...
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### If photons have mass then how can they travel at speed of light? [closed]

Anything that has mass must be slower than speed of light. If they are travelling at speed of light they must contain infinite energy which should be able to destroy everything, clearly thats not ...
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### Does a single photon's energy depend on frequency? (photoelectric effect)

Essentially this question boils down to "why does the energy of light depend on frequency?". The analogy my textbook (pg. 272 principles of chemistry A molecular Approach 3rd edition by Nivaldo J. ...
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### Can one photon emit two electrons?

My question refers to the photoelectric effect. I have heard that it is possible, that for one photon, two electrons leave the irradiated metal. Is this correct and by which process can this be ...
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### Does nature of light depends on its Time of Interaction?

I was trying to understand how to "feel" about light. I have formed a notion which I couldn't find anywhere. So please tell if I am correct. Also please give theoretical explanations if possible (and ...
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### Photoelectric effect and energy of light

I have a doubt about photoelectric effect and the nature of light in general. From what I understood, in order to ionize a piece of some material, I need an electromagnetic wave with a frequence ...
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### Relationship Between Stopping Voltage and Photocurrent

Online, I found a graph of photocurrent vs. stopping voltage: And I canâ€™t figure out how photocurrent and stopping voltage have such a relationship. Stopping voltage is proportional to maximum KE ...
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### Einstein's 1905 “Concerning an Heuristic…emission and transformation of light”

I'm currently attempting to read Einstein's annus mirabilis papers, starting with his introduction of the quantization of light in the paper: "Concerning an Heuristic Points of View Toward the ...
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### Effect of frequency on magnitude of photo current

In a photoelectric experiment, if the frequency of incident light is slightly raised while holding intensity constant, I understand that the number of incident photons decreases. This in turn results ...
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### Why does wavelength determine the energy of a photon?

The professor for my first-year university chemistry class remarked that the wavelength of a photon determines its energy. Why is it that the case? I've only completed high-school physics so far, so ...
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### Why does current vary continuously with potential in the photoelectric effect?

In the photoelectric effect, for a given intensity and frequency of light source, why does the current increase as you decrease the retarding potential, below the stopping potential. Isn't the ...
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### Can I use fluorescent light bulbs to calculate Planck's constant?

We did an experiment today to calculate Planck's constant, $h$. We measured the knee voltages $V$ of different LEDs (red, green, orange, blue, violet) and plotted them against the frequencies $f$ of ...
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### Dependence of saturation current in photoelectric tube on the time taken by the electron to reach the opposite plate?

The kinetic energy of an electron in a photoelectric tube increases with increase in the applied voltage across the plates of the tube, thus the velocity of the electrons also increases. Accordingly ...
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### Can electron jumps to higher energy state without absorbing photon?

The shorter the wavelength of the electromagnetic wave the more energy it carries, when it hits an atom and gets absorbed the electron gains kinetic energy and jumps to higher energy state. Are there ...
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### Why is the K shell electron preferred in the photo electric effect?

I have read in many books and on Internet as well that photoelectric effect is only possible when an electron is emitted from the K shell of the metal. Why not other bonded electrons?
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### Light and momentum question? [duplicate]

Each photon of light bulb carries momentum. Why does the light bulb not recoil from conservation of momentum?
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### What's the difference between the work function and ionisation energy?

In a particular textbook, the work function of a metal (in the context of the photoelectric effect) is defined as: the minimum amount of energy necessary to remove a free electron from the surface ...
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### Dissolving photoconductor (TiOPc) from Laser Printer drum possible?

When I was thinking of a Lab-On-a Chip Application which combines a lensless microscope and an optical tweezers I saw the ODEP-concept:(http://pubs.rsc.org/en/content/articlelanding/2013/lc/c3lc50351h#...
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### Is the photon's wave function the same as an electromagnetic wave(light)? [duplicate]

The first that i have been taught in Quantum Mechanics is the photoelectric phenomenon. Without analyzing it, it concludes that when we shine light at the circuit(roughly speaking), the work required ...
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### Would an ordinary or fluorescent lightbulb generate electricity when exposed to light?

I was wondering whether the physic laws or the nature in which lightbulbs are constructed would allow for lightbulb to generate electricity when subjected to strong (intensive and concentrated) light.....
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### Why don't electrons dislodge with higher intensity?

I understand that photo-electrons are not produced with increased intensity because frequency is what matters, however could someone give me a good intuition of why this is the case? What exactly do ...
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### How to calculate the potential of a photocell?

My guess is that because the wire is connected to a single point on the plate, we can treat it as a point charge and use the formula: $$V = k\frac{k(\pm q)}{|r|}$$ But I think there are different ...
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### How does the maximum kinetic energy of an ejected electron affect what happen to it after being ejected? [duplicate]

So I just learned: $$K_{max} = hf - \phi$$($\phi$ for ionization energy) I wonder what will happen if $K_max$ is zero. Will it be attracted back to the ionized atom it has come from since it doesn't ...
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### Will ionization energy be affected by screening effect?

It would be logical to think that the more electrons are ejected from an atom, the harder it is to eject more. I just learned about photoelectric effect experiment. The book is kinda telling me the ...
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### Quantum efficiency of Photoelectric effect

What is the typically measured quantum efficiency of photoelectric effect experiments involving ultra violet photons incident upon common metals like copper or aluminum. In case I'm not being clear, ...
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### What if I double the frequency of incident light in photoelectric effect?

The photoelectric effect occurs when the frequency of incident radiation is above a threshold frequency. If we double this incident frequency, what effect will it have on the experiment? Also what ...
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### Photoelectric Effect - Dependence of current on frequency

We all know that the amount of current flowing b/w the plates is independent of the frequency. If I were to ask why doesn't it depend then you'd probably say that it depends on the number of electrons ...
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### How long does it take for an excited electron to return to ground state?

During a mock Cambridge interview, one of the questions was about how small a computer could theoretically be.The way I approached it was in terms of what something must be to be considered a computer....