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An extremely Novice energy question

  1. Apr 16, 2010 #1

    khz

    User Avatar

    I'm sure this has been thoroughly answered, so I'm sorry.
    So, you have e=mc2, yet when you have food (or anything) before consumption and after consumption, the mass of both atomic states is equal, yet the form of the former state (before consumption) gives the mass more energy potential than the latter state.
    ?
     
  2. jcsd
  3. Apr 16, 2010 #2

    Dale

    Staff: Mentor

    Actually, the mass is slightly less in the less energetic state. This is called "mass deficit". The difference is very small for chemical reactions.
     
  4. Apr 16, 2010 #3

    khz

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    oh wow thanks. Are you aware if this effect has been measured?
     
  5. Apr 16, 2010 #4

    Dale

    Staff: Mentor

    Yes, for nuclear reactions. To my knowledge it is too small to measure for chemical reactions.
     
  6. Apr 16, 2010 #5

    SpectraCat

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    Science Advisor

    Actually, very high resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometers can already reproducibly measure mass differences that are significantly smaller than the electron mass. I have seen at least one experiment proposed to measure the "electronic mass defect" associated with a chemical reaction, however I think the technology was still not quite adequate to the task.
     
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