The mass of proton, neutron and helium nucleus are respectively 1 . 0073 u , 1 . 0087 u and 4 . 0015 u . The binding energy of helium nucleus is:

Step-by-step solution

Given here, m He = 4 . 0015   u , m p = 1 . 0073   u and m n = 1 . 0087   u . Mass defect ∆ m   =   2 m p + 2 m n - m He = 2 × 1 . 0073 + 2 × 1 . 0087 - 4 . 0015 = 0 . 0305   u Binding energy E   =   ∆ m × 931   MeV = 0 . 0305 × 931 = 28 . 4   MeV