Question

15) Why is critical mass important for a fission chain reaction?

A. It keeps neutrons from escaping the sample.
B. It keeps neutrons from being absorbed by other isotopes.
C. It allows neutrons to be absorbed by other fissionable nuclei.
D. It provides enough fuel to make enough energy.

16) Why is a moderator important for a fission chain reaction?
A.It keeps neutrons from escaping the sample.
B.It keeps neutrons from being absorbed by other isotopes.
C. It allows neutrons to be absorbed by other fissionable nuclei.
D. It provides enough fuel to make enough energy.

17) Why is enrichment important for a fission chain reaction?
A. It keeps neutrons from escaping the sample.
B. It keeps neutrons from being absorbed by other isotopes.
C. It allows neutrons to be absorbed by other fissionable nuclei.
D. It provides enough fuel to make enough energy.

Answer 1

Step-by-step explanation:

The correct answer is C. Critical mass is the minimum amount of fissionable material required to sustain a chain reaction. If the amount of fissionable material is less than the critical mass, the reaction will not be self-sustaining. When the critical mass is reached, each fission event releases neutrons that can be absorbed by other fissionable nuclei, leading to a chain reaction.

The correct answer is C. A moderator is a material that is used to slow down the neutrons produced by fission. Slow-moving neutrons are more likely to be absorbed by other fissionable nuclei, leading to a sustained chain reaction. Without a moderator, the neutrons would move too quickly and pass through the fissionable material without causing fission.

The correct answer is B. Enrichment is the process of increasing the concentration of fissionable isotopes in a material, usually uranium-235. A higher concentration of uranium-235 means that more neutrons will be absorbed by fissionable nuclei, leading to a sustained chain reaction. Without enrichment, the concentration of uranium-235 is too low to sustain a chain reaction.

cheif keef