The graph of binding energy per nucleon as a function of mass number shows a maximum around iron.
Answer the following questions related to this observation.
(i) Explain, with reference to the shape of the graph, why both the fission of very heavy nuclei such as 235U and the fusion of very light nuclei such as hydrogen isotopes are accompanied by the release of energy.
(ii) Using the idea of energy released per single nuclear event (about 200MeV for fission of 235U and about 17.6MeV for the fusion of 12H with 13H), describe qualitatively how these microscopic energy values can lead to macroscopic energy outputs measured in megawatt-hours.
(iii) Contrast the energy density (energy released per unit mass of fuel) of nuclear fuels with that of a typical chemical fuel such as coal (≈30MJkg−1). State two practical implications of this contrast for power generation plants.