Question

1.) Name an element that cannot release energy through either fusion or fission. (Uranium?)

2.) Compare the abundance of fuel for nuclear fusion and fission reactions. (No clue)

Thanks for helping

Answer 1

(1) There is a graph between Binding energy per nucleon and Mass number. From this graph we see that binding energy per nucleon reaches a maximum of 8.8 MeV at A=56, corresponding to the iron nucleus ₂₆Fe⁵⁶. So iron is most stable and hence it neither release energy through fission nor through fusion.

Besides average binding energy per nucleon is about 8.5 MeV and this is the case for the atoms having mass number ranging between 40 and 120. All these elements are stable and do not take part in fission reaction or fusion reaction.

Binding energy per nucleon for Uranium is 7.6 MeV which is much lower than average value and hence it release energy through fission. Fusion occcurs at the low mass number atoms due to the exactly same reason as Uranium. Here those atoms release energy through fusion to increase the binding energy per nucleon.

(2) Both nuclear fission and fusion are capable of releasing huge amount of energy. There are large number of heavy atoms which can emit energy. Non-fissionable isotopes of heavy atoms can be transformed into fissionable isotopes.Thats why nuclear fission is now largest source of energy.

In spite of that nuclear fusion (though uncontrollable till now) has greater potential to release greater energy than fission. There is no shortage of fuel for nuclear fusion but it is difficult to extract energy from them in a controlled manner. The main fuel for fusion is hydrogen due to its lowest mass. Whereas there are large number of fissile isotopes like Thorium,Uranium,Polonium etc.