Question

The binding energies per nucleon for deuteron and helium are $1.1$ MeV and $7$ MeV respectively. Calculate the energy released when two deuterons fuse to form a helium nucleus.

• A. 23.6 MeV
• B. 25.8 MeV
• C. 19.2 MeV
• D. 28.8 MeV

Answer 1

The correct option is A 23.6 MeV

We use the energy released as positive energy,
Deutrons Helium
1 neutrons 2 neutrons
1 protons 2 protons
For breaking of one Deutron
Energy released $=-1.1-1.1Mev$
$=-2.2Mev$
For 2 Deutrons$=-4.4Mev$
Energy released to form 1 Helium from
protons and neutrons$=7\times 4Mev=28Mev$
so, for $2_1^{2}H{\to }_2^{4}He.$
Total energy released$=(-4.4+28)Mev$
$=23.6Mev$