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MHT CET 2024 (15 May, Shift 1) · Law of Radioactive Decay

Law of Radioactive Decay question from MHT CET 2024 (15 May, Shift 1)

Q21MHT CET 2024 · 15 MAY · SHIFT 1Easy

Law of Radioactive Decay

A radioactive substance has half-life of 60 minutes. During 3 hours, the amount of substance decayed would be

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Answer: (d)

$3\text{ h} = 180\text{ min}$ , so $n = \frac{180}{60} = 3$ half-lives.
Remaining $= \left(\frac{1}{2}\right)^3 = \frac{1}{8} = 12.5\%$ .
Decayed $= 100\% - 12.5\% = 87.5\%$ .
So the answer is (d) $87.5\%$ .

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