Radioactivity (safety): Given the half-lives below, which radioactive isotope would be the most dangerous to handle (highest activity per amount)? Assume equal initial amounts; shorter half-life ⇒ greater activity. Choose the correct option.

Difficulty: Easy

3 billion years
100 years
0.01 minute
13 days

Correct Answer: 0.01 minute

Explanation:

Concept/Approach
Activity A ∝ λ (decay constant), and λ = ln2 / T_½. Thus, for the same number of nuclei, shorter half-life means higher activity and greater handling hazard.

Comparison
T_½ = 0.01 min (≈0.6 s) ≪ 13 days ≪ 100 years ≪ 3 billion years.

Final Answer
0.01 minute

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