Question

What is required for a uncontrollable chain reaction to take place?

A. A fusion reaction

B. Enough alpha particles

C. A critical mass

D. All of the above

Answer 1

Answer is option C (A critical mass)

if the radioactive matierial does not pocess a critial mass,uncontrollable chain reaction will not happen.

A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, the nuclear fission cross-section), its density, its shape, its enrichment, its purity, its temperature, and its surroundings