1. A proton has three quarks. Let there be n up quarks in a proton, each having a charge of (+2/3) e. Charge due to n up quarks =(2/3 x e)n Number of down quarks in a proton = 3 - n Each down quark has a charge of = -1/3 x e Charge due to (3 - n) down quarks =  (-1/3 x e) (3 — n) Total charge on a protRead more

    A proton has three quarks. Let there be n up quarks in a proton, each having a charge of (+2/3) e.

    Charge due to n up quarks =(2/3 x e)n

    Number of down quarks in a proton = 3 – n

    Each down quark has a charge of = -1/3 x e

    Charge due to (3 – n) down quarks =  (-1/3 x e) (3 — n)

    Total charge on a proton = + e

    Therefore e = (2/3 x e) n + (-1/3 x e) (3 — n)

    => e = 2ne/3  – e + ne/3

    => 2 e = ne => n = 2

    Number of up quarks in a proton, n = 2

    Number of down quarks in a proton = 3- n = 3 — 2 = 1 .

    Therefore, a proton can be represented as ‘uud’.

    A neutron also has three quarks. Let there be n up quarks in a neutron.

    Charge on a neutron due to n up quarks = (+2/3 e )n

    Number of down quarks is  3-n ,and each having a charge of -1/3 e.

    Charge on a neutron due to (3-n) down quarks = (-1/3e) (3-n)

    Total charge on a neutron =0

    Therefore 0=(2/3 x e) n + (-1/3 x e) (3-n)

    =>  0 = 2ne/3  –  e  +  ne/3

    => e= ne =>n=1

    Number of up quarks in a neutron ,n=1

    Number of down quarks in a neutron=3-n =2

    Therefore, a neutron can be represented as ‘udd’.

     

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