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the half-life of radium-226 is 1.6x10^3 year. How many hours will it take for a 2.50-g sample to decay to the?

the half-life of radium-226 is 1.6x10^3 year. How many hours will it take for a 2.50-g sample to decay to the point where 0.185 g of the isotope remains?

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  • Anonymous
    7 years ago

    N = No * e ^ [ - 0.6931 * t / t1/2 ]

    [ - 0.6931 * t / t1/2 ] = ln[ N / No ]

    t = [ - t1/2 / 0.6931 ] * ln[ N / No ]

    t = [ - 1.60E3 / 0.6931 ] * ln[ 2.5 / 0.185 ]

    t = 6011 years or 5.27E7 hours <===ans

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