The half-life of the radioactive substance is 40 days. The substance will disintegrate completely in - Physics

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MCQ

The half-life of the radioactive substance is 40 days. The substance will disintegrate completely in

Options

  • 40 days

  • 400 days

  • 4000 days

  • infinite time

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Solution

infinite time

Explanation:

The time it takes for a substance to completely dissolve is infinite. 

log`"N"_0/0 = λt`

⇒ log`"N"_0/0 = λt`

log ∞ = λt

hence when N → 0, t → ∞ 

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