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Topic: Need help calculating the frequency of an absorbed photon  (Read 1493 times)

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Offline Baronwalrus1

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Need help calculating the frequency of an absorbed photon
« on: September 22, 2018, 12:00:47 PM »
Apologies in advance for any poor formatting I tried to follow the page on proper formatting, but I have never posted here before. I was working on a review for an upcoming chem test I had when I came across a question with a confusing answer. The question was: Calculate the frequency of a photon absorbed when the hydrogen atom undergoes a transition from n=2 to n=4 (R=1.0968*10^7). the answer is apparently 6.169*10^14 Hz. When I used the equation V=R(\frac 1 {n^2_1} - \frac {1}{n^2_2} I got 2.056*10^6 Hz. I tried dividing the keys given answer by R and got roughly 56,000,000. According to the formula for frequency above that would mean \frac 1 {4} - \frac 1 {16} = 56,000,000. What is it that I am missing? I attached a picture of the question as well.


Offline Enthalpy

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Re: Need help calculating the frequency of an absorbed photon
« Reply #1 on: September 24, 2018, 09:44:35 AM »
Welcome, Baronwalrus1!

What is the unit of R here?

And: what kind of electromagnetic radiation do you expect can make an n=2 to n=4 transition? What are typical frequencies for such radiations? Or wavelengths, if you prefer.

You must know dozens of such guides. Everyone makes mistakes. Scientists wouldn't let a 108 mistake pass through.

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