chemistry

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What percent of the original sample of strontium-90 (half-life = 28.9 years) will remain after the following time periods?after 18 years?
after 47.5 years?

after 1008 years?

  • chemistry -

    k = 0.693/t1/2
    ln(No/N) = kt
    Substitute into equation 1 and solve for k, the substitute into equation 2 and solve for N. No will be 18, 47.5, 1008 years.

  • chemistry -

    .....it's actually asking for the % left after so many years

  • chemistry -

    So N = amount left.
    % = (N/No)*100 = ?

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