NEET-XII-Physics
13: Nuclei
- #3Obtain the binding energy (in MeV) of a nitrogen nucleus
, given
=14.00307 u
Ans : Atomic mass of nitrogen
, m = 14.00307 u
A nucleus of nitrogen
contains 7 protons and 7 neutrons.
Hence, the mass defect of this nucleus, Δm = 7mH + 7mn - m
Where,
Mass of a proton, mH = 1.007825 u
Mass of a neutron, mn= 1.008665 u
∴Δm = 7 × 1.007825 + 7 × 1.008665 - 14.00307
= 7.054775 + 7.06055 - 14.00307
= 0.11236 u
But 1 u = 931.5 MeV/c2
∴Δm = 0.11236 × 931.5 MeV/c2
Hence, the binding energy of the nucleus is given as:
Eb = Δmc2
Where,
c = Speed of light
∴Eb = 0.11236 × 931.5
= 104.66334 MeV
Hence, the binding energy of a nitrogen nucleus is 104.66334 MeV.