13.3 Obtain the binding energy (in MeV) of a nitrogen nucleus \(\left({ }_{7}^{14} \mathrm{~N}\right)\), given mass of nitrogen nucleus, \(m_\left({ }_{7}^{14} \mathrm{~N}\right)\)=14.00307 u.

Hint: The binding energy can be obtained by finding the mass defect in the nitrogen nucleus.
Step 1: Find the mass defect in the nitrogen nucleus.
The atomic mass of N714 nitrogen, m = 14.00307 u
A nucleus of N714 nitrogen contains 7 protons and 7 neutrons.
Hence, the mass defect of this nucleus, m=7mH+7mn-m
where,
Mass of a proton, mH = 1.007825 u
mass of a neutron, mn = 1.008665 u
Mass defect,
m=7×1.007825+7×1.008665-14.00307=0.11236 u
But 1 u=931.5 MeV/c2
m=0.111236×931.5 MeV/c2
Step 2: Find the binding energy of nitrogen nucleus.
Hence, the binding energy of the nucleus is given as:
Eb=mc2 where, c= speed of light 
Eb=0.11236×931.5MeVc2c2=104.66334 MeV
Hence, the binding energy of a nitrogen nucleus is 104.66334 MeV.