Final answer:
The products of the fission of heavy nuclei like promethium typically include medium-weight nuclei, neutrons, and energy. Alpha particles are not produced by the fission process but are rather associated with certain types of radioactive decay.
Step-by-step explanation:
Items not produced by the fission of heavy nuclei, like promethium, do not include medium-weight nuclei, neutrons, or liberated energy. These are actually common products of a nuclear fission reaction.
However, alpha particles are not typically produced in the fission process itself but are instead commonly associated with radioactive decay processes in certain isotopes.
The process of fission involves a nucleus splitting into two smaller nuclei, alongside the release of neutrons and a significant amount of energy, due to the conversion of mass to energy as described by Einstein's equation E = mc².
The statistical nature of fission means that a variety of products can be produced, but alpha particles are not one of them.