Question:
The activity of a radioactive sample decreases to 25% of its initial value in 60 days. The half-life is:
The activity of a radioactive sample decreases to 25% of its initial value in 60 days. The half-life is:
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25% remaining means two half-lives have passed.
Updated On: Jan 5, 2026
- 30 days
- 60 days
- 20 days
- 40 days
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The Correct Option is A
Solution and Explanation
25% = \((1/2)^2\), so 2 half-lives = 60 days.
\[
T_{1/2} = 30\ \text{days}
\]
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