Question

the production of electricity from fission nuclear reactions in power plants is regulated by controlling the amount of electrons available. the amount of uranium available. the amount of protons available. the amount of neutrons available.

Explanation:

In nuclear fission power plants, the chain - reaction is regulated by controlling neutrons. Neutrons are used to initiate and sustain the fission process. By controlling the number of neutrons available, the rate of the nuclear reaction can be adjusted, thus regulating electricity production. Electrons, protons, and the overall amount of uranium are not directly used to regulate the reaction rate in this way.

Answer:

the amount of neutrons available.