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Homework Help: Moles of electrons that weigh 1 kg

  1. Jun 28, 2015 #1
    1. The problem statement, all variables and given/known data
    How many moles of electrons weigh 1 kg?

    2. Relevant equations

    3. The attempt at a solution
    We know the mass of an electron= 9.1*10-31kg. So no of electrons in one Kg will be 1/9.1*10-31. Then we just divide that by 6* 1023 to get the number of moles. But my teacher told me that i need to first convert the mass into grams for the calculations. Does it matter in this case since we're dealing with electrons?
    Last edited: Jun 28, 2015
  2. jcsd
  3. Jun 28, 2015 #2


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    Staff: Mentor

    As the mass of electron is already expressed in kg, there is no need to convert it and your approach is perfectly correct. However in future please don't omit units - I had to check 9.1×10-31 is a mass of an electron expressed in kg to be sure you are right.
  4. Jun 28, 2015 #3
    sorry about that. And thank you sir.
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