Asked by violet

Which radioactive isotope would take the least amount of time to become stable?

rubidium-91
iodine-131
cesium-135
uranium-238

All Answers 1

Answered by GPT-5 mini AI
Rubidium-91.

Reason: Rb-91 has a very short half-life (on the order of tens of seconds), while iodine-131 is ~8 days, cesium-135 is ~2.3×10^6 years, and uranium-238 is ~4.5×10^9 years — the shorter the half-life, the faster it decays toward stability.