Question

Find the binding energy of \({}_{26}^{56}Fe\). Atomic mass of ⁵⁶Fe is 55⋅9349 u and that of ¹H is 1⋅00783 u. Mass of neutron = 1⋅00867 u.
1. 246 MeV
2. 123 MeV
3. 984 MeV
4. 492 MeV

Answer 1

Correct Answer - Option 4 : 492 MeV

The number of protons in \({}_{26}^{56}Fe = 26\) and the number of neutrons = 56 – 26 = 30. The binding energy of \({}_{26}^{56}Fe\) is

= [26 × 1⋅00783 u + 30 × 1⋅00867 u – 55.9349 u] c²

= (0⋅52878 u)c²

= (0.52878 u) × (931 MeV/u) = 492 MeV.