Answer:
0.5 g
Explanation:
The half-life of a radioactive isotope is the time it takes for a certain amount of that isotope to halve.
In this case, we have an isotope of Americium-241, which has a half-life of
[tex]\tau = 432 y[/tex]
This means that after 1 half-life (432 years), there will be an amount of americium equal to half its initial amount.
In this problem, the initial amount of americium is
[tex]m_0 = 1 g[/tex]
Therefore, after 432 years (1 half-life), the amount of americium left will be half:
[tex]m(432y) = \frac{m_0}{2}=0.5 g[/tex]
