Question

The masses of neutron and proton are 1.0087 amu and 1.0073 amu respectively. If the neutrons and protons combine to form a helium nucleus (alpha particles) of mass 4.0015 amu. The binding energy of the helium nucleus will be [1 amu= 931 MeV]

• A. 28.4 MeV
• B. 20.8 MeV
• C. 27.3 MeV
• D. 14.2 MeV

Answer 1

Answer: (A)

28.4 MeV

Answer 2

Helium nucleus consist of two neutrons and two protons.

So binding energy E = ∆m amu = ∆m × 931 MeV

⇒ E = (2 × m_p + 2m_n – M) × 931 MeV = (2 × 1.0073 + 2 × 1.0087 – 4.0015) × 931 = 28.4 MeV