Answer:
[tex]a=64.7mg[/tex]
Explanation:
Hello,
In this case, we need to remember that for the required time for a radioactive nuclide as radium-226 to decrease to one half its initial amount we are talking about its half-life. Furthermore, the amount of remaining radioactive material as a function of the half-lives is computed as follows:
[tex]a=a_0(\frac{1}{2} )^{\frac{t}{t_{1/2}} }[/tex]
Therefore, for an initial amount of 100 mg with a half-life of 1590 years, after 1000 years, we have:
[tex]a=100mg(\frac{1}{2} )^{\frac{1000years}{1590years} }\\\\a=64.7mg[/tex]
Best regards.