Question

the ratio of carbon - 14 (¹⁴c) to its stable isotope, carbon - 12 (¹²c), is relatively constant in living organisms and their environment; however, this changes once an organism dies. in a fossil approximately 40,000 years old, the ratio of ¹⁴c to ¹²c would be higher because the ¹²c is not replenished after death. ratio of ¹⁴c to ¹²c would be lower because the ¹⁴c is not replenished after death. ratio of ¹⁴c to ¹²c would not change because the ¹⁴c is replenished after death. ratio of ¹⁴c to ¹²c would be equal (1:1). ¹⁴c would be completely gone; all remaining carbon by this time would be ¹²c.

Explanation:

Carbon - 14 is a radioactive isotope that decays over time, while carbon - 12 is stable. In living organisms, the ratio of carbon - 14 to carbon - 12 is maintained as carbon - 14 is replenished. But after death, the replenishment of carbon - 14 stops and it continues to decay, reducing its amount relative to carbon - 12.

Answer:

The ratio of $^{14}C$ to $^{12}C$ would be lower because the $^{14}C$ is not replenished after death.