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Homework Help: Easy chem question

  1. Sep 13, 2009 #1
    Calculate the change in energy when the following transition occurs in the hydrogen atom.

    n = 4 ----> n = 1


    E = -Rh/n^2

    eventually my answer is 2.04E-18J because my book tells me to take 1 over n(low) squared minus 1over n(high) squared and multiply by rydberg constant.. so doing it according to the book i get a positive number

    but the answer is -2.04E-18J.... and now after looking online... im getting serveral mixed sources, some saying that it is positive, others saying it is negative.. which is it.
  2. jcsd
  3. Sep 13, 2009 #2


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  4. Sep 14, 2009 #3


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    Staff: Mentor

    This is change in energy. Whatever atom loses is gained by surroundings, so sign if the change is either negative or positive, depending on the point of view.

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