Explanation:
<h3>oxidation of Nitrogen in N2O3 is </h3><h2>+3</h2>
Answer: 0.125mg americium
Half-lives is a set of duration when a sample will become half of their original mass. In this case, the initial mass is 1mg and the sample is going for 3 times half-lives. Then the calculation would be: 1mg

= 1/8 mg= 0.125mg.
Great question, let me know if you get the anwser!