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Fermium-253 is a radioactive isotope of fermium that has a half-life of 3.0 days. A scientist obtained a sample that contained 216 micrograms of fermium-253.

Complete the table to show how much fermium-253 should remain in the sample at the indicated times after the scientist obtained the sample.

\begin{tabular}{|c|c|}
\hline
\begin{tabular}{c}
Time \\
Elapsed
\end{tabular} & \begin{tabular}{c}
Amount \\
Remaining
\end{tabular} \\
\hline
3.0 days & [tex]$108 \mu g$[/tex] \\
\hline
6.0 days & [tex]$\square \mu g$[/tex] \\
\hline
9.0 days & [tex]$\square \mu g$[/tex] \\
\hline
\end{tabular}



Answer :

Let's complete the table step-by-step, discussing how much fermium-253 remains at each specified time interval.

### Given:
- Half-life of Fermium-253: 3.0 days
- Initial amount of Fermium-253: 216 micrograms

### Explanation:
The remaining amount of a substance after a certain time period can be calculated using the formula:
[tex]\[ \text{Remaining Amount} = \text{Initial Amount} \times \left( \frac{1}{2} \right)^{\frac{\text{Elapsed Time}}{\text{Half-life}}} \][/tex]

For 3.0 days:
- Time Elapsed: 3.0 days
- Elapsed Time / Half-life: [tex]\( \frac{3.0}{3.0} = 1 \)[/tex]

[tex]\[ \text{Remaining Amount after 3.0 days} = 216 \times \left( \frac{1}{2} \right)^{1} = 216 \times 0.5 = 108.0 \text{ micrograms} \][/tex]

For 6.0 days:
- Time Elapsed: 6.0 days
- Elapsed Time / Half-life: [tex]\( \frac{6.0}{3.0} = 2 \)[/tex]

[tex]\[ \text{Remaining Amount after 6.0 days} = 216 \times \left( \frac{1}{2} \right)^{2} = 216 \times 0.25 = 54.0 \text{ micrograms} \][/tex]

For 9.0 days:
- Time Elapsed: 9.0 days
- Elapsed Time / Half-life: [tex]\( \frac{9.0}{3.0} = 3 \)[/tex]

[tex]\[ \text{Remaining Amount after 9.0 days} = 216 \times \left( \frac{1}{2} \right)^{3} = 216 \times 0.125 = 27.0 \text{ micrograms} \][/tex]

### Table:

[tex]\[ \begin{tabular}{|c|c|} \hline \begin{tabular}{c} Time \\ Elapsed \end{tabular} & \begin{tabular}{c} Amount \\ Remaining \end{tabular} \\ \hline 3.0 days & 108.0 \text{ micrograms} \\ \hline 6.0 days & 54.0 \text{ micrograms} \\ \hline 9.0 days & 27.0 \text{ micrograms} \\ \hline \end{tabular} \][/tex]

So, the amounts remaining at the specified times are 108.0 micrograms after 3.0 days, 54.0 micrograms after 6.0 days, and 27.0 micrograms after 9.0 days.