The binding energy per nucleon of `._(3)^(7) Li` and `._(2)^(4)He` nuclei are `5.60` MeV and `7.06` MeV, respectively. In the nuclear reaction `._(3)^(7)Li+._(1)^(1)H rarr ._(2)^(4)He+._(2)^(4)He+Q`, the value of energy `Q` released is

Options

A. 19.6 MeV
B. `-2.4` MeV
C. 8.4 MeV
D. 17.3 MeV

Explanation

Binding energy of `""_(3)^(7)Li` nucleus
`=7xx5.60 MeV=39.2MeV`
Binding energy of `""_(2)^(4)He" nucleus "=4xx7.06MeV = 28.24 MeV`
The reaction is
`""_(3)^(7)Li+""_(1)^(1)Hrarr 2(""_(2)^(4)He)+Q`
`=2xx28.24MeV-39.2MeV=56.48 MeV-39.2MeV`
`=17.28MeV~~17.3MeV`