Physics

Problem

(a) Draw a rough sketch of the variation of average binding energy per nucleon

\bar E

with mass number

A

for nuclei from

A=1

A\approx 240

. (b) Using the salient features of your sketch, explain separately why (i) fusion reactions involving very light nuclei (e.g.

^{2}\!\mathrm H

^{3}\!\mathrm H

) can liberate energy, and (ii) fission reactions of very heavy nuclei (e.g.

^{235}\!\mathrm U

^{238}\!\mathrm U

) can also liberate energy. (c) The average binding energy per nucleon for deuterium is

1.1\,\text{MeV}

, whereas that for helium-4 is

7.1\,\text{MeV}

. Calculate the energy released when two deuterium nuclei fuse to form one helium-4 nucleus (ignore any other emitted particles). a. Draw sketch of

\bar E

A

b. Explain energy release for fusion (light) and fission (heavy) c. Calculate energy released in

^{2}\!\mathrm H+{}^{2}\!\mathrm H\rightarrow{}^{4}\!\mathrm{He}