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Topic: How do I calculate the Rydberg Constant?  (Read 13908 times)

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Offline aFarDay

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How do I calculate the Rydberg Constant?
« on: November 09, 2010, 07:59:17 PM »
I was just curious as to how Rydberg came to the conclusion that the Rydberg Constant was approximately  2.18x10^(-18) Joules.

I know The equation is
 RH = me4 / 8E02h2
where  h is plancks constant,  E0 is permitivity constant, M is electron mass, and e is electron charge.

If i put these #'s in will i get 2.18x10^(-18) J?
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Also why is the Rydberg Constant on wikipedia different from the one in my textbook? (zumdahl)



Will Dividing the Rydberg constant by the principal quantum number times -1. Will that give  me En ,the binding energy?

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thank you for your help, we are on this chapter but my teacher isn't going in depth with this specific topic in the class.  :)

Offline Borek

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Re: How do I calculate the Rydberg Constant?
« Reply #1 on: November 10, 2010, 04:29:33 AM »
If i put these #'s in will i get 2.18x10^(-18) J?

Have you tried? 1 minute of keying the digits into the calculator and you will know.

Also why is the Rydberg Constant on wikipedia different from the one in my textbook? (zumdahl)

Do they use the same units?
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Offline aFarDay

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Re: How do I calculate the Rydberg Constant?
« Reply #2 on: November 10, 2010, 10:49:37 AM »
If i put these #'s in will i get 2.18x10^(-18) J?

Have you tried? 1 minute of keying the digits into the calculator and you will know.

Also why is the Rydberg Constant on wikipedia different from the one in my textbook? (zumdahl)

Do they use the same units?

I have tried and I didn't get anything close to it. I'm sure that there are a lot of different values for those constants in various units. So i don't know which values to plug in.

yeah the value on wikipedia has you multiply the speed of light and another Planck's constant on the denominator.

My calculator gives me either 0 or an error because the #'s are too small and it rounds after about x10-60

Offline Jorriss

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Re: How do I calculate the Rydberg Constant?
« Reply #3 on: November 10, 2010, 11:04:51 AM »
What values are you using for all those inputs?

Offline Borek

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Re: How do I calculate the Rydberg Constant?
« Reply #4 on: November 10, 2010, 11:14:24 AM »
My calculator gives me either 0 or an error because the #'s are too small and it rounds after about x10-60

Windows calculator is capable of much higher accuracy (that's assuming you are on Windows). But there is a trick you can use - think if you can change oder of calculations so that your intermediates never get outside of the applicable range.
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