Question

(a) In a typical nuclear reaction, e.g. 12H + 21H → 32He + n + 3.27MeV, although number of nucleons is conserved, yet energy is released. How? Explain.

(b) Show that nuclear density in a given nucleus is independent of mass number A

Answer 1

(a) In nuclear reaction
12H + 12H → 23He + n + 3.27MeV
Cause of the energy released:
(i) Binding energy per nucleon of 23He becomes more than the (BE/A) of 12H.

(ii) Mass defect between the reactant and product nuclei

(b) The radius of nucleus of mass number A is given by R = R0A1/3

The expression of the density is independent of mass number A.