What is the minimum amount of uranium-235 necessary for a critical mass?

Question

Quizplus · Accepted Answer

The minimum amount of uranium-235 necessary for a critical mass is the amount that is sufficient to sustain a chain reaction. This is because a critical mass is defined as the smallest amount of fissile material (in this case, uranium-235) needed for a sustained chain reaction. Options A, B, and C give specific measurements of the amount of uranium-235, but do not necessarily represent the minimum critical mass. Option E mentions explosive fission, which is not necessarily related to sustaining a chain reaction. Therefore, D is the best choice.

What Is the Minimum Amount of Uranium-235 Necessary for a Critical