Answer:
2.15 mg of uranium-238 decays
Explanation:
For decay of radioactive nuclide-
[tex]N=N_{0}.(\frac{1}{2})^{\frac{t}{t_{\frac{1}{2}}}}[/tex]
where N is amount of radioactive nuclide after t time, [tex]N_{0}[/tex] is initial amount of radioactive nuclide and [tex]t_{\frac{1}{2}}[/tex] is half life of radioactive nuclide
Here [tex]N_{0}=4.60 mg[/tex], [tex]t=4.1\times 10^{9}yr[/tex] and [tex]t_{\frac{1}{2}}=4.5\times 10^{9}yr[/tex]
So,[tex]N=(4.60mg)\times (\frac{1}{2})^{\frac{4.1\times 10^{9}}{4.5\times 10^{9}}}[/tex]
so, N = 2.446 mg
mass of uranium-238 decays = (4.60-2.446) mg = 2.15 mg
