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The mass m(t) remaining after t days from a 70 g sample of thorium-234 is given by the equation shown below.
m(t) = 70e-0.0274t

Find the half-life of thorium-234. (Round your answer to the nearest tenth.)

  • math -

    you would be solving

    35 = 70 e^-.0274t
    .5 = e^-.0274t
    -.0274t = ln(.5)
    t = ln(.5)/-.0274
    = 25.297

    half life is appr 25.3 years

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