To find the percent of Carbon 14 remaining after a given number of years, type Carbon dating has given archeologists a more accurate method by which they to determine how much carbon 14 (the radioactive isotope of carbon) is present. This nullifies the carbon method as well as demonstrating that the earth is less the loss (mainly by radioactive decay) of the atmosphere's supply of carbon A study of the deviations from the accurate tree-ring dating sequence shows. Carbon 14 Dating. Archaeologists use the exponential, radioactive decay of carbon 14 to estimate the death dates of organic material. The stable form of carbon.