Final answer:
The student's question concerns the amount of a 500-gram sample of a carbon isotope remaining after a certain period, related to the concept of half-life in radioactive decay. However, the time period is not provided, prohibiting an exact calculation.
Step-by-step explanation:
The student's question seems to be incomplete, but it appears to be about the radioactive decay of carbon (parent isotope) over time. Specifically, the student may be asking how much of a pure 500-gram sample would remain after a certain period, possibly relating to carbon-14's half-life which is 5,730 years. Without the specified time frame (which is missing in the question), we can't calculate the exact amount remaining. However, using radioactive decay principles, we know that the amount of a radioactive sample decreases by half every half-life period. So, after one half-life (5,730 years for Carbon-14), there would be 250 grams left, after two half-lives (11,460 years), 125 grams would remain, and this pattern would continue with each half-life. Additionally, as the radioactive atoms decay, they are replaced with their decay products, which are termed as daughter elements.