Radiocarbon, or carbon-14, is a radioactive isotope of carbon that is formed in the atmosphere when cosmic rays interact with nitrogen. It is incorporated into carbon dioxide, which plants absorb during photosynthesis. Animals and humans then consume these plants, making radiocarbon a part of their biological systems. Scientists use radiocarbon dating to determine the age of organic materials, such as wood, bone, and cloth, up to about 50,000 years old. By measuring the remaining amount of carbon-14 in a sample, researchers can estimate when the organism died, providing valuable information about historical events and archaeological findings.