This document discusses methods for determining the age of objects, including radioactive dating using carbon-14. Radioactive elements like carbon-14 decay at a steady rate, allowing scientists to calculate an object's age by comparing the amounts of stable and unstable atoms. Specifically, carbon dating works because carbon-14 is absorbed by plants and animals while alive but then decreases after death, following the radioactive half-life. By measuring carbon-14 and carbon-12 levels, the time since a plant or animal died can be estimated.