12. Dinosaur fossils are too old to be reliably dated usingcarbon-14. (See Exercise 11.) Suppose we had a 68-million-year-old dinosaur fossil. What fraction of the living dino-saur's ¹4C would be remaining today? Suppose the minimumdetectable amount is 0.1%. What is the maximum age of afossil that we could date using ¹4C? 11. Scientists can determine the age of ancient objects by themethod of radiocarbon dating. The bombardment of the upperatmosphere by cosmic rays converts nitrogen to a radioactiveisotope of carbon, ¹C, with a half-life of about 5730 years.Vegetation absorbs carbon dioxide through the atmosphere andanimal life assimilates ¹4C through food chains. When a plantor animal dies, it stops replacing its carbon and the amount of14C begins to decrease through radioactive decay. Thereforethe level of radioactivity must also decay exponentially.A discovery revealed a parchment fragment that had about74% as much ¹4C radioactivity as does plant material on theearth today. Estimate the age of the parchment.

Answered: Image /qna-images/answer/0d44e86b-fcd5-4571-ae10-c4c5991cc456.jpg

12. Dinosaur fossils are too old to be reliably dated using carbon-14. (See Exercise 11.) Suppose we had a 68-million- year-old dinosaur fossil. What fraction of the living dino- saur's ¹C would be remaining today? Suppose the minimum detectable amount is 0.1%. What is the maximum age of a fossil that we could date using ¹4C?