chemistry

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a sample of sodium-24 with an activity of 12 mCi is used to study the rate of blood flow in the circulatory system. If sodium-24 has a half-life of 15 h, what is the activity of the sodium after 2.5 days. please show work.

  • chemistry -

    1). half life = ln(2) / lambda

    where lambda is the radioactive decay constant

    2). A(t) = 12mCi * e ^ - (lambda * t)

    where t is time, A(t) is activity as a function of time


    15 hr = ln2 / lambda

    solve for lambda

    convert 2.5 days to hours
    Then t = 2.5 days * (24 hrs / day)

    Plug these numbers into A(t)

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