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Energy released from heavy atoms?

  1. May 3, 2012 #1

    Now I've noticed something about nuclear fission and fusion. They both are small atoms that release megawatts of energy that could destroy most of big cities. Now I wonder how is that possibile? Splitting an atom create MAJOR amounts of heat and energy combined what is the reason for that? The only thing that comes from my head is the force that is holding the protons and neutrons together is smashed with another atom.

    Im talking about heavy atoms not the simple ones because in every single second atom collided with each other.

    I'm confused on how a small small particle create a HUGE energy burst that puzzels me honestly.

    I feel sometimes they don't follow the laws of thermodynamics nor conservation of energy but I don't know what the input energy is in the first place to compare lol.
  2. jcsd
  3. May 3, 2012 #2
    Have you read the topic binding energy per nucleon or something like this?...
    if yes then think this in such a way..
    You first pull all atoms apart by applying some force. then let them to combine and make a new nucleus.. in case of heavy nucleus you will find the a lot of energy is released..
    law of conservation of energy is not valid in such cases(E=mc2)..
  4. May 3, 2012 #3


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    Gold Member

    Hypo, There is a big difference between nuclear fission and nuclear fusion...the two processes you mention.

    Fission is the splitting of a "large" nucleus into two "smaller" ones, plus the liberation of energy. Example: Atomic bomb over Hiroshima, Japan.

    Fusion is the "fusing" of two hydrogen nuclei together to create one helium nucleus, plus the liberation of energy. Example: Our sun.

    Both processes give off great quantities of "atomic energy", in contrast to "chemical energy" we get from, say, dynamite. To understand where this energy comes from you need to learn some nuclear phycics!

    Google is your friend, please Google those terms and learn to use this valuable resource for your own education. Wikipedia usually gives good "starting point" explanations. Don't forget to check the "for further reading" and the "references" near the bottom of Wiki pages for more details.
  5. May 3, 2012 #4


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    Staff: Mentor

    Wikipedias articles on nuclear fission and fusion will explain this pretty well. And you can follow the other links around to learn more.
  6. May 4, 2012 #5
    This is actually where Einstein's famous E=mc^2 equation came from. For the longest time, physicists were puzzled because nuclear fission reactions seemed to slightly violate the law of conservation of mass. If this small amount of destroyed matter is converted to energy with the above equation, this ends up being equal to the energy generated by the fission process, leading to the modified conservation of mass-energy law (they are equivalent to one another according to (E^2) = (m^2) (c^4) + (p^2) (c^2).)
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