How Much Energy Does an Electron Retain from Blue-Green Light?

AI Thread Summary
An electron in metallic cesium absorbs a photon of blue-green light (5x10^-7 m) and retains a portion of its energy after escaping the metal's attractive forces. The color of the light is identified as blue-green, which falls between the wavelengths of blue and green light. The discussion highlights the need for calculations to determine the exact percentage of energy retained by the electron. Comparisons of the energies of the photons from different wavelengths are also emphasized. Understanding these concepts is crucial for solving the homework problem effectively.
Marcus James
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Homework Statement



If an electron in metallic cesium absorbs a photon of red light (6.6x10^-7) m in vacuum), all the energy is used up in escaping from the attractive forces in the metal. Suppose light with 5x10^-7 is used, what percentage of the photon's energy does the electron retain after it has escaped from the metal? What color light is this?

Homework Equations

The Attempt at a Solution



I believe the light color would be that of Blue-Green.[/B]
 
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And why do you think that? Do you have any math to support it?
 
Because Blue-Green is the medium between Blue (4.5-5)x10^-7 and Green (5.0-5.7)x10^-7, as the light in this example is 5x10^-7, so it falls between the two. Have you any though on the first question?
 
Marcus James said:
Have you any though on the first question?
How do the energies of the two photons compare?
 

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