Suppose a laboratory has a 26-gram sample of polonium-210.The half-life of polonium-210 is about days. a.How many half-lives of polonium-210

Question

Suppose a laboratory has a 26-gram sample of polonium-210.The half-life of polonium-210 is about days. a.How many half-lives of polonium-210 occur in 276 days? b.How much polonium is left in the sample after 276 days?

in progress 0
Eden 3 weeks 2021-09-25T22:08:46+00:00 2 Answers 0

Answers ( )

    0
    2021-09-25T22:09:53+00:00

    Answer:

    a) Two half lives, b) m(276) = 6.526\,g

    Step-by-step explanation:

    a) The polonium-210 has a half life of 138.4 days. Therefore, 1.994 half lives have past.  

    b) Mass decay is described by the following exponential model:

    m(t)=m_{o}\cdot e^{-\frac{t}{\tau} }

    The time constant for the isotope is:

    \tau = \frac{138.4\,days}{\ln 2}

    \tau = 199.669\,days

    The mass of the isotope after 276 days is:

    m(276) = (26\,g)\cdot e^{-\frac{276\,days}{199.669\,days} }

    m(276) = 6.526\,g

    0
    2021-09-25T22:10:30+00:00

    Answer:

    Step-by-step explanation:

    Given:

    t1/2 = 138 days

    t = 276 days

    No = 26 g

    t/t1/2 = 276/138

    = 2 half-lifes

    N(t) = No × (1/2)^(t/t1/2)

    = 26 × (1/2)^2

    N(276 days) = 6.5 g

Leave an answer

45:7+7-4:2-5:5*4+35:2 =? ( )