Consider the nuclear reaction, `""_1H^2 + ""_1H^2 to ""_2He^4 + Q` . What is the value of Q if mass of `""_1H^2 = 2.0141 u " and mass of " ""_2He^4` = 4.0024 u.

Options

A. 20 MeV
B. 22 MeV
C. 24 MeV
D. 30 MeV

Answer

C

Explanation

This is a fusion reaction in which two deutrium nuclei (ligh nuclei) fuse to form a heavy nucleus `""_2He^4`
Mass defect `Delta m= 2xx " mass of " ""_1H^2 - " mass of " ""_2He^4`
`=2xx2.0141 - 4.0024`
`=0.0258 u`
But 1u = 9331 MeV (From `E = mc^2` )
`therefore Q = 0.0258xx931 MeV = 24 MeV`