Lead-214 has a half-life of 43.5 seconds. What percent of a sample of this isotope would be left after a time equivalent to 7 half-lives?

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Lead-214 has a half-life of 43.5 seconds. What percent of a sample of this isotope would be left after a time equivalent to 7 half-lives?

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Khoii Minh 5 years 2021-07-27T16:50:44+00:00 1 Answers 17 views 0

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  1. Xavia
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    2021-07-27T16:51:51+00:00
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    Answer:

    Explanation:

    Lead has an half life of 43.5 seconds

    The radioactive decay law says

    N(t) = No•2^(-t / t½)

    Hence, the percent of a sample of the Lead-214 isotope that decay after a time equivalent to 7 half-lives

    ​N(t) = No•2^(-t / t½)

    N(t) / No = 2^(-t / t½)

    N(t) / No = 2^-7

    N(t) / No = 7.81 × 10^-3

    To percentage

    N(t) / No = 7.81 × 10^-3 × 100

    N(t) / No = 0.781 %

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