A copper coin has a mass of 63.0g. Calculate the nuclear energy that would be required to separate all the neutrons and protons form each other. The coin is entirely made of `""_(29)^(63)Cu` atoms.
Mass of `""_(29)^(63)Cu` atom = 62.92960u
mass of proton = 1.00727u
Mass of neutron = 1.00866u
Avogadro's number = `6.022 xx 10^(23)`

Explanation

Mass defect per copper nucleus:
`Deltam=Zm_(p)+(A-Z)m_(n)-M_(cu)`
`Deltam=(29xx1.00727)+(34xx1.00866)-62.92960`
`Deltam=0.5757u` Energy required to separate neutrons and protons in one nucleus (is equal to binding energy )
`E_(b)=Deltamxx931.5MeV`
`E_(b)=0.5757xx931.5=536.3 `MeV
Number of atoms in the copper coin (mass=63 g) is
`N=6.022xx10^(23)`
Total energy required to separate all neutrons and protons in the coin =`E_(b)xxN`
`E=536.3xx6.022xx10^(23)` Or `3.23xx10^(26)MeV`
OR `E=5.17xx10^(13)J`
Note :(1)Full marks should be awarded if 931 MeV or
932 MeV is used while finding binding energy .
(2)Full marks should be awarded if `M_(C_(u))` =[Mass of copper atom -29 X mass of electron] is used .
i.e., Mass of copper nucleus :
M or `M_(C_(u))=62.92960-(29xx0.00055)=62.9316 u`
Mass defect:`Deltam`=0.59167 u,B.E, `E_(b)`=551.1 MeV
and total energy ,E=`3319xx1023 MeV` .