Photon energy and calculating frequency

AI Thread Summary
A photon with an energy of 2.12 eV converts to approximately 3.392 x 10^-19 joules. To find the frequency, the equation E = hv is used, leading to a calculated frequency of 5.12 x 10^14 Hz. This frequency is reasonable as it falls within the visible spectrum when converted to wavelength. Some participants noted that converting to joules may not be necessary depending on the context. The discussion emphasizes the importance of verifying calculations and understanding the relationship between energy, frequency, and wavelength.
MathiasArendru
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Hello guys, I am having a bit of trouble with some homework

So I am told that a photon in a light beam has an energy og 2,12 eV. First i have to calculate the energy of it in joules, and since 1 eV is 1,60*10^-19 Joules 2,12 eV in joules is just 2,12*1,60*10^-19 = 3.392*10−19 J i got that.
Then i have to calculate the frequency of the light beam. I use the equation E = hv and just isolate v to get v = e/h. When i then plug in the numbers i get v = 3.392*10−19/6.63*10^-34(plancks constant) = 5.12*10^14 seconds. But isn't that a huuuge frequency? Anything I've done worng?

Thanks in advance!
 
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You shouldn't need to convert to joules. You should have a value for Planck's constant that is eV•s.

Also, if you're unsure what a reasonable frequency is, convert it to wavelength, and then see where that wavelength falls on the spectrum and compare that to the question. In this case if you convert to wavelength you'll find that this pretty much in the middle of the visible spectrum.
 
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Actually you're right haha, when i first heard it, it just seemed like too much and i didnt think about it any further but obviously it is. and converting to joules was a task included in the assignment.
Thanks
 
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