NEET-XII-Physics

46: The Nucleus

with Solutions - page 4
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  • #5
    Find the binding energy per nucleon of
    79197Au if its atomic mass is 196.96 u.
    Ans : Given:
    Atomic mass of Au, A = 196.96
    Atomic number of Au, Z = 79
    Number of neutrons, N = 118
    Binding energy, `` B=(\,\mathrm{\,Z\,}{m}_{p}+N{m}_{n}-M){c}^{2}``
    `` ``
    `` ``
    Here, mp = Mass of proton
    M = Mass of nucleus
    mn = Mass of neutron
    c = Speed of light
    On substituting the respective values, we get
    `` B=\left[\right(79\times 1.007276+118\times 1.008665)\,\mathrm{\,u\,}-196.96\,\mathrm{\,u\,}]{c}^{2}``
    `` =\left(198.597274-196.96\right)\times 931\,\mathrm{\,MeV\,}``
    `` =1524.302094\,\mathrm{\,MeV\,}``
    Binding energy per nucleon `` =\frac{1524.3}{197}=7.737\,\mathrm{\,MeV\,}``
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