Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

B Can someone walk me through nuclear fission?

  1. Jun 4, 2016 #1
    Its been a long time since ive studdied chemistry, I used to have a pretty decent understanding of it, but ive forgotten some of it.

    I remember that the energy produced from a fission reaction has to do with the number of bonds being broken, and that bonding energy released is obscenely high wich is why most fission reactions are performed with complex elements becuase they have more bonds to break, and are natrually unstable.

    But what is this concept of critical mass? How does a fission chain reaction start? What makes one perticular element a better fissile fuel?
  2. jcsd
  3. Jun 4, 2016 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Yes, it has been a long time for you.

    The first thing you must do is wrap your head around the idea that fission is not a chemical process at all, but a nuclear one. The amount of energy released in a fission reaction has nothing to do whatsoever with any chemical bonds being broken. In a fission reaction, the nucleus of the fissile atom is split into at least two smaller atomic fragments, which also means that one element is split into two other elements.

    Why don't you read up on fission and then come back with any questions on stuff which may not be clear to you?

    This is a good article with which to start:

  4. Jun 4, 2016 #3


    User Avatar
    Staff Emeritus
    Science Advisor

    Hyperphysics has some good articles.


    A critical mass is a configuration that maintains a chain reaction. A neutron source is used to initiate 'controlled' chain reaction.

    Critical (k = 1) means that the power is constant. Supercritical (K > 1) means that power (or neutron population) is increasing, and subcritical means (k < 1) means power is decreasing, or constant but requires an external source.
  5. Jun 4, 2016 #4
    I didnt mean chemical bonds. I ment the bonds of the nucleus of the atom
  6. Jun 4, 2016 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper

    Not sure what you mean there.

    The binding energy of the original nucleus is greater than the total binding energy of the daughter nuclei resulting from fission. It is this difference in binding energy which is released when an atom is split.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted