The mass of a `a_3^7 Li` nucleus is `0.042 u` less than the sum of the masses of all its nucleons. The binding energy per nucleon of `._3^7 Li` nucleus is nearly.

Options

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

Answer

B

Explanation

(b) If `m = 1u, c = 3 xx 10^8 ms^-1`, then
`E = 931 MeV` i.e., `1u = 931 MeV`
Binding energy `xx 0.042 xx 931 = 39.10 MeV`
` :.` Binding energy per nucleon
=`(39.10)/(7) = 5.58 ~~ 5.6 MeV`.