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

The correct option is A 28.4 MeV

Helium nucleus consist of two neutrons and two protons.
So binding energy $E=\Delta m\times 931MeV$
$\Rightarrow E=(2\times m_p+2m_n-M)\times 931MeV=(2\times 1.0073+2\times 1.0087-4.0015)\times 931=28.4MeV$