​ The mass of ^7_3Li a nucleus is 0.042 u less than the sum of the masses of all its nucleons.

Question

The mass of a \(^7_3Li\) nucleus is 0.042 u less than the sum of the masses of all its nucleons. The binding energy per nucleon of \(^7_3Li\) nucleus is nearly

(a) 46 MeV 

(b) 5.6 MeV 

(c) 3.9 MeV 

(d) 23 MeV

Answer 1

(b) 5.6 MeV

If w = 1 u, C = 3 x 10⁸ ms^-1 

then, E = 931 MeV

1 u = 931 Mev

Binding energy = 0. 042 x 931

= 39. 10 MeV 

∴ B.E 39.10

Binding energy per nucleon = \(\frac{B.E}{A}\) = \(\frac{39.10}{7}\)

5.58 = 5.6 MeV