Carbon-14, also called radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples. Carbon-14 was discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley.
Radiocarbon dating is a technique used by scientists to learn the ages of biological specimens – for example, wooden archaeological artifacts or ancient human remains – from the distant past. It can be used on objects as old as about 62,000 years. By comparing the placement of objects in time using radiocarbon dating with known age references like calendars and tree rings, scientists can construct a highly accurate timeline for events that have occurred over tens and hundreds of thousands of years.
Today, carbon-14 atoms are used extensively in many medical procedures including cancer treatments and diagnosis, radiation therapy planning and image-guided surgery . In addition to its clinical uses, carbon-14 has become an important tool for researchers studying a wide range of topics from climate change to marine ecology.