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NEET 1989 (AIPMT) · Law of Radioactive Decay

Law of Radioactive Decay question from NEET 1989 (AIPMT)

Q124NEET 1989 · AIPMTEasy

Law of Radioactive Decay

A radioactive element has half life period 800 years. After 6400 years what amount will remain?

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Answer: (d)

$n = \frac{6400}{800} = 8$ half-lives.
Fraction left $= \left(\frac{1}{2}\right)^8 = \frac{1}{256}$ .
So the answer is (d) $1/256$ .

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