Photoelectric effect, and sunlight.

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Discussion Overview

The discussion revolves around the photoelectric effect, specifically whether sunlight has sufficient intensity to eject electrons from metal atoms. Participants explore the relationship between light frequency, intensity, and the conditions necessary for the photoelectric effect to occur.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions if sunlight has a high enough intensity to knock electrons out of metal, acknowledging that the frequency is likely sufficient.
  • Another participant clarifies that the photoelectric effect depends on frequency rather than intensity, stating that a single photon can eject an electron if its energy is adequate.
  • A different participant asserts that visible light cannot knock out electrons, while X-rays can, but notes that atmospheric conditions may block higher frequency radiation.
  • Some participants express confusion about the ability of blue light to eject electrons, indicating a misunderstanding of the frequency requirements.
  • A participant references a Wikipedia article that discusses the threshold frequency for various metals, suggesting that visible light can be sufficient for some metals but not others.

Areas of Agreement / Disagreement

Participants exhibit uncertainty regarding the specific frequencies of light that can cause the photoelectric effect in different metals. There is no consensus on whether sunlight, particularly visible light, is adequate for this purpose.

Contextual Notes

Participants mention the role of atmospheric absorption in determining which frequencies reach the metal, indicating that the discussion may depend on specific conditions and definitions of intensity and frequency.

kcajrenreb
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Hello, I apologize if this question makes no sense, or is stupid, but I would just like to clarify something.

Is the light that comes from the sun a high enough intensity to "knock" any electrons out of the atoms in a metal? I know it is a high enough frequency, and I think the intensity is high enough, but I'd just like to make sure.

Thank you very much, and again I apologize if my question made little sense.
 
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The photoelectric effect is independent of intensity. A single photon can knock an electron out of metal as long as the frequency is high enough, aka it has enough energy. Intensity merely causes MORE electrons to be knocked out per unit of time.
 
kcajrenreb said:
Hello, I apologize if this question makes no sense, or is stupid, but I would just like to clarify something.

Is the light that comes from the sun a high enough intensity to "knock" any electrons out of the atoms in a metal? I know it is a high enough frequency, and I think the intensity is high enough, but I'd just like to make sure.

Thank you very much, and again I apologize if my question made little sense.

Visible light cant.
X-ray i think can knock out an electron of almost everything.
The problem is if they can get to your metal. most of UV and higher get blocked by the atmosphere.
 
Really? I thought that blue light on the visible spectrum was a high enough frequency to "knock" the electrons out of metal, I guess I thought wrong. Thanks for your answers both of you.
 
kcajrenreb said:
Really? I thought that blue light on the visible spectrum was a high enough frequency to "knock" the electrons out of metal, I guess I thought wrong. Thanks for your answers both of you.

From wikipedia:
When a surface is exposed to electromagnetic radiation above a certain threshold frequency (typically visible light for alkali metals, near ultraviolet for other metals, and extreme ultraviolet for non-metals), the radiation is absorbed and electrons are emitted. Light, and especially ultra-violet light, discharges negatively electrified bodies with the production of rays of the same nature as cathode rays.

The article is here:http://en.wikipedia.org/wiki/Photoelectric_effect
 

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