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Homework Help: Rest Mass Energy of Neutron?

  1. Mar 9, 2009 #1
    1. The problem statement, all variables and given/known data
    What is the rest mass energy of one mole of neutrons? Hint one mole is 6.02 x 1023 particles (avocado's number), and the neutron has mass m=1.675 x 10 -27 kg.


    2. Relevant equations



    3. The attempt at a solution

    I wasn't sure of the relationship between moles and mass. What I attempted to do was multiply one mole by the mass. Then plugged in the equation of E=mc2. I came up with the answer of 9.075 x 10 16. This just doesn't seem right. Any help would be appreciated.
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Mar 9, 2009 #2
    I think it's perfectly correct as long as the value you have used for the neutrons mass is indeed its rest mass. Why doesn't it seem right to you?

    ----

    (Me being a lazy boy I didn't check that you actually put the right values in your calculator)

    As posted below one mole of neutrons is equal to 6.02 x 10^23 neutrons, which you multiply by the neutrons mass to get the total mass. Then it's a cake piece of.
     
    Last edited: Mar 9, 2009
  4. Mar 9, 2009 #3

    Andrew Mason

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    Homework Helper

    Show us your work. What numbers did you multiply? What results? Units? You appear to be out by a few orders of magnitude.

    A mole is just what is stated. It is Avogadro's number of particles. So a mole of neutrons is 6.02 x 10^23 neutrons.

    AM
     
  5. Mar 9, 2009 #4
    thanks for everyone's help
     
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