### Rydberg constant

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**Fri Oct 14, 2016 1:31 am**On the equation sheet, the Rydberg constant is equal to 3.28984*10^15, but on the fall 2014 quiz 1 preparation, the answer for question 10 said otherwise. It uses an equation where R is equal to -2.178*10^-18. Why are there two values for this constant and which one am I supposed to use?