Suppose a sample of a certain substance decayed to 63.2% of its original amount after 300 days. (Round your answers to two decimal places.) (a) What is the half-life (in days) of this substance? Need Help? Read It Submit Answer 3. [0/5 Points] PREVIOUS ANSWERS SCALCET9 3.8.011. Scientists can determine the age of ancient objects by the method of radiocarbon dating. The bombardment of the upper atmosphere by cosmic rays converts nitrogen to a radioactive isotope of carbon, 14C, with a half-life of about 5,730 years. Vegetation absorbs carbon dioxide through the atmosphere, and animal life assimilates e through food chains. When a plant or animal dies, it stops replacing its carbon, and the amount of 14c present begins to decrease through radioactive decay. Therefore, the level of radioactivity must also decay exponentially. A discovery revealed a parchment fragment that had about 56% as much He radioactivity as does plant material on the earth today. Estimate the age (in years) of the parchment. (Round your answer to the nearest hundred years.) 5 x oyr Submit