(04.06 HC)
C12/C14 Ratio

\begin{tabular}{|c|c|}
\hline
Organism & C12/C14 Ratio \\
\hline
[tex]$X$[/tex] & [tex]$8 \times 10^{12}$[/tex] \\
\hline
[tex]$Y$[/tex] & [tex]$2 \times 10^{12}$[/tex] \\
\hline
[tex]$Z$[/tex] & [tex]$1 \times 10^{12}$[/tex] \\
\hline
\end{tabular}

What can most likely be concluded from the above information?

A. Only Organism [tex]$Z$[/tex] is alive, and Organism [tex]$X$[/tex] has been dead longer than Organism [tex]$Y$[/tex].
B. Only Organism [tex]$Z$[/tex] is alive, and Organism [tex]$Y$[/tex] has been dead longer than Organism [tex]$X$[/tex].
C. Only Organism [tex]$X$[/tex] is alive, and Organism [tex]$Y$[/tex] has been dead longer than Organism [tex]$Z$[/tex].
D. Only Organism [tex]$X$[/tex] is alive, and Organism [tex]$Z$[/tex] has been dead longer than Organism [tex]$Y$[/tex].



Answer :

To determine the most likely conclusion based on the C12/C14 ratios for the given organisms, we need to understand the relationship between these ratios and the time since death.

The C12/C14 ratio is used in radiocarbon dating to determine the age of an organism since its death. Carbon-14 ([tex]\(^14C\)[/tex]) is a radioactive isotope that decays over time, while Carbon-12 ([tex]\(^12C\)[/tex]) is a stable isotope. When an organism dies, it stops absorbing [tex]\(^14C\)[/tex], and the existing [tex]\(^14C\)[/tex] begins to decay. Therefore, the higher the C12/C14 ratio, the longer the organism has been dead, because more [tex]\(^14C\)[/tex] has decayed relative to the amount of [tex]\(^12C\)[/tex].

Given the C12/C14 ratios:
- Organism X: [tex]\(8 \times 10^{12}\)[/tex]
- Organism Y: [tex]\(2 \times 10^{12}\)[/tex]
- Organism Z: [tex]\(1 \times 10^{12}\)[/tex]

We can conclude the following based on these ratios:
1. Organism Z has the smallest C12/C14 ratio of [tex]\(1 \times 10^{12}\)[/tex]. This implies that it has the highest amount of [tex]\(^14C\)[/tex] relative to [tex]\(^12C\)[/tex], meaning it is the most recently alive or still living.
2. Organism Y has a C12/C14 ratio of [tex]\(2 \times 10^{12}\)[/tex], which is higher than Z's ratio but lower than X's ratio. This implies that Y has been dead longer than Z but shorter than X.
3. Organism X has the highest C12/C14 ratio of [tex]\(8 \times 10^{12}\)[/tex]. This suggests that X has been dead the longest among the three organisms.

Therefore, from the given information, the most accurate conclusion is:
Only Organism Z is alive, and Organism Y has been dead longer than Organism X.