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ChemistryInteger+4 / -1Question 85 of 90

JEE Main 2022 · 29 Jul · Shift 2, Chemistry question 85

Assuming 1 μg of trace radioactive element X with a half life of 30 years is absorbed by a growing tree. The amount of X remaining in the tree after 100 years is _______ ×10−1\times10^{-1} μg.

[Given: ln 10 = 2.303; log 2 = 0.30]

Answer and worked solution

Official answer: 1

Decay. 1×2−100/30=2−3.33≈0.0991\times2^{-100/30}=2^{-3.33}\approx0.099 μg ≈1×10−1\approx1\times10^{-1} μg.

Answer: 1

Topics:Half-lifeRadioactive decay kinetics
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