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    why do fission reactions have to be induced? in the book it goes on about the liquid drop model but dont actualy see what it has to do with anything

    thanks
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    Wikipedia says that the free neutron is absorbed by the nucleus, making the nucleus unstable so that it will then split into multiple smaller nuclei.
    Does it also have something to do with giving the nucleons enough energy to break the Coulomb barrier? I might be getting that confused with why fusion requires high temperatures
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    My reckoning is when a neutron is absorbed, it increases the diameter of the nuclei. This means that the overall electrostatic force of repulsion between protons becomes greater than the strong force (because the strong force only works in limited range of a few femtometres, but by increasing the diameter of the nuclei you've decreased its effectiveness), so more repulsion and the nuclei breaks apart.
    Also you can say that the addition of a neutron distorts the nuclei.
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    (Original post by sarah12345)
    why do fission reactions have to be induced? in the book it goes on about the liquid drop model but dont actualy see what it has to do with anything thanks
    the neutron distorts the nucleus enough to destabalise it and so it breaks apart because of the now unbalanced distribution of forces.
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    My reckoning is when a neutron is absorbed, it increases the diameter of the nuclei. This means that the overall electrostatic force of repulsion between protons becomes greater than the strong force (because the strong force only works in limited range of a few femtometres, but by increasing the diameter of the nuclei you've decreased its effectiveness), so more repulsion and the nuclei breaks apart.
    But surely by adding an extra neutron will actually decrease the electrostatic force because there will be a greater distance between protons? Also, the extra neutron won't actually have any effect on the strong force, because, sure, you are increasing the diameter of the nuclues, but that's only because you have added an extra particle which itself will add to the strong force. Hmmm, I'm getting confused...
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    is this edexcel???
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    I think it is simply what the book says, the liquid drop model of the nucleus means that it is inclined to adopt a stable spherical shape with lowest PE, and therefore this requires energy to distort it and break it up, energy comes from the absorption of a neutron
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    (Original post by mackin boi)
    is this edexcel???
    its physics
 
 
 
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