Question

The binding energies per nucleon for deuteron (`._1H^2`) and helium (`._2He^4)` are `1.1 MeV` and `7.0 MeV` respectively. The energy released when two deutrons fuse to form a helium nucleus (`._2He^4`) is……..
A. `13.9 MeV`
B. `26.9 MeV`
C. `23.9 MeV`
D. `19.2 MeV`

Answer 1

Correct Answer - C
( c) Total binding energy of helium atom `(2 He^4)`
=`4 xx 7 = 28 MeV`
Total binding energy of deutron `_1 H^2 (1 p + 1n)`
=`2 xx 1.1 = 2.2 MeV`
`:.` Binding energy of `2` deuterons
=`2 xx 2.2 = 4.4 MeV`
So, the energy released in forming helium nucleus from two deuterons.
=`(28 - 4.4) MeV = 23.6 MeV`.