1. Why is a moderator needed in a normal uranium fission reactor?
(a) To increase the rate of neutron capture by uranium-235.
(b) To increase the rate of neutron capture by uranium-238.
(c) To increase the rate of production of plutonium-239.
(d) To increase the critical mass of the fission fuel.
(e) To provide more neutrons for the reaction.
(f) All of the above.
2. What is the difference between nuclear fission and nuclear fusion?
(a) Nuclear fission is used for bombs; nuclear fusion is used in power plants.
(b) There is no difference. Fission and fusion are different names for the same physical phenomenon.
(c) Nuclear fission refers to using deuterium to create a nuclear reaction.
(d) Nuclear fusion occurs spontaneously, as happens to the C14 used in carbon dating.
(e) In nuclear fission, a nucleus splits; in nuclear fusion, nucleons or nuclei and nucleons join to form a new nucleus.