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Thread: neutron

  1. #1 neutron 
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    ok, i was touching up on my chemistry, and well... i started pretty much at the start of the book. (now your wondering.. wht the fcuk is he posting in the physics board?)

    well i gotsa reading on the atom and its discoverys... and i was wondering if the nuetron had any use?

    what dose it do?
    why is it stuck in the middle?

    is it necccesary?

    what happens when you take it away? dose the atom blow up? ie.. is that what happens in necular reactions?

    BTW: i started the post with the first bit.. now its comming a bit clear... er?

    oh.. and another thing.. i just got da ja vu... did i post this already ?

    but it is a serious question!


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  3. #2  
    Forum Professor wallaby's Avatar
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    in the atom protons and electrons attract each other because of there opposite charge.

    in a nucleus with multiple protons we get the protons trying to repel each other, and so this little particle called a Neutron which holds them in place and stops the neucleus of the attom flying apart.

    the number of neutrons in a nucleus can also affect the stability of an atom and its isotopes, if you have too many in a nucleus the atom undergoes a proccess of radioactive decay untill it has formed a stable atom.

    http://science.howstuffworks.com/nuclear1.htm


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  4. #3  
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    Quote Originally Posted by wallaby
    Neutron which holds them in place and stops the neucleus of the attom flying apart.
    i thhought so .. when posting i remembered, but i still had to be sure!!!
    cheers
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  5. #4  
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    Actually its the gluon which holds the nucleus together. The neutron has a significance because its presence is the very cause of the nuclear properties of the atom.
    Like for eg.
    C12 is different from C14 cause change in the number of neutrons. The neutron hence changes the properties of those isotopes.
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  6. #5  
    Moderator Moderator Janus's Avatar
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    Quote Originally Posted by kakarot
    Actually its the gluon which holds the nucleus together. The neutron has a significance because its presence is the very cause of the nuclear properties of the atom.
    Like for eg.
    The neutron does play a role in holding the nucleus together. For example, you will never see a Helium 2 isotope. Even though the strong force can bind proton to proton, it is just a little too weak to form purely a proton-proton bond. The neutron of Helium 3 provides that extra bit of strong force binding needed to hold things together.
    The strong force holding the nucleus together also seems to have a preference for neutron-proton pairs. This likely explains why Helium 4 (2 protons and 2 neutrons) makes of 99.999% of naturally occurring Helium.

    So every nucleus larger than 1 nucleon must have at least 1 neutron, the larger the nucleus, the more neutrons needed for stability. For example, Lithium 4 and 5 can form, but have extremely short half-lives. Lithium 6 and 7 are stable.

    To many neutrons are not good for stability either. Lithium 8-12 are unstable also. The isolated neutron is unstable and has a half-life of 15 min. Extra neutrons can decay via beta emission (neutron converts to proton while emitting an electron and anti-neutino).

    A stable nucleus tends toward a balance between proton and neutron number. Some combinations are more stable than others. There are what are called the "magic numbers" (2, 8, 20, 28, 50, 82, 126..) Nuclei with this many nucleons tend to be more stable. "Double magic" nuclei have both the number of protons and neutrons each equal to a magic number (the above mentioned Helium 4, for example) and tend to be even more stable. Calcium 48 is double magic and is stable even though it at first appears to have an excess number of neutrons (Calcium 47 is unstable, as is Calcium 49 while Calcium 46 is stable. Also, the heaviest stable nuclide , Lead 208, is double magic.

    The exact reason behind magic numbers is not quite understood yet. One possible explanation is that nucleons are arranged in shells much the same way that electrons are and the magic numbers represent the filling of shells.


    C12 is different from C14 cause change in the number of neutrons. The neutron hence changes the properties of those isotopes.
    Just to be clear, it changes the nuclear properties, including stability, but the chemical and physical properties remain the same. (other than the slight change in density.) C12 and C14 form the same compounds, which is why it is useful for dating objects that are organic in origin. Plants take it in from the atmosphere and use it just like C12 in their tissues, which allows us to date when it died and quit taking in C14.
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  7. #6  
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    Oh!!
    Thanks a lot!
    I learnt a lot more than I ever could by joining this forum.

    Thanks again!!!!
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