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A radioactive substance has a half life of 2.5 days. How much of 25.0 z is left after 10 days? ​

1 Answer

4 votes

1.563 g

Further explanation

Given

A half life of 2.5 days ⇒ t1/2 = 2.5 days

initial sample ⇒ 25 g

duration of decay ⇒ 10 days

Required

sample left after 10 days

Analysis

Use decay Formula :


\tt Nt=No.(1)/(2)^(T/t1/2)

Solution


\tt Nt=25.(1)/(2)^(10/2.5)\\\\Nt=25.(1)/(2)^4\\\\Nt=\boxed{\bold{1.563~g}}

Paraphrase

Substance left after 10 days = 1.563 g

User Andrew Axton
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