How does critical mass play a role in nuclear reactions?

Question

A. It is the minimum amount of material needed to start a fission reaction.
B. It is the minimum amount of material needed to start a fusion reaction.
C. It is the minimum amount of material needed to sustain a fission reaction.
D. It is the minimum amount of material needed to sustain a fusion reaction.

Answer 1

The correct answer is: C. It is the minimum amount of material needed to sustain a fission reaction.

In the context of nuclear fission, critical mass refers to the smallest amount of fissile material required to maintain a self-sustained chain reaction. If the amount of material is below this threshold, the reaction will not sustain itself, and the majority of the neutrons produced will escape without causing further fission.