Question

Calculate the binding energy of an alpha particle in MeV. Given

mass of a proton = 1.007825 u

mass of a neutron = 1.008665 u

mass of He nucleus = 4.002800 u

1u = 931 MeV/c²

Answer 1

Mass defect = (Mass of protons + mass of neutrons) – (Mass of He nucleus)

\(\Delta m = (2m_p+ 2m_n) - m_{He}\) 

\(= (2 \times 1.00782u) + (2 \times 1.008665u)- 4.002800u\) 

\(\text{Binding energy} = \Delta m \times c^2\)

Given 1 u = 931 MeV/c²

^{\(\therefore \ \)} Binding energy = 0.03017 u × 931 MeV

= 28.088 MeV