The mass of a `""_(7)^(3)Li` nucleus is 0.042 u less than the sum of the masses of all its nucleons. The binding energy per nucleon of `""_(7)^(3)Li` nucleus is nearly

Options

A. 46 MeV
B. 5.6 MeV
C. 3.9 MeV
D. 23 MeV

Explanation

If m =1u, `C= 3 xx 10^(8)ms^(-1)` then, E=931 MeV
1 u = 931 Mev
Binding energy `=0.042 xx 931`
=39. 10 MeV
Binding energy per nucleon `=(B.E)/(A) = (39.10)/(7) = 5.58 =5.6 MeV`