Radioactive carbon dating method

This tendency to decay, called radioactivity, is what gives radiocarbon the name radiocarbon.The atmosphere contains many stable carbon atoms and relatively few radiocarbon atoms.Ever wondered how scientists know the age of old bones in an ancient site or how old a scrap of linen is?The technique used is called carbon dating and in this lesson we will learn what this is and how it is used. Carbon dating, or radiocarbon dating, is a method used to date materials that once exchanged carbon dioxide with the atmosphere. In the late 1940s, an American physical chemist named Willard Libby first developed a method to measure radioactivity of carbon-14, a radioactive isotope.

Some examples of the types of material that radiocarbon can determine the ages of are wood, charcoal, marine and freshwater shell, bone and antler, and peat and organic-bearing sediments.

Working with several collaboraters, Libby established the natural occurrence of radiocarbon by detecting its radioactivity in methane from the Baltimore sewer.

In contrast, methane made from petroleum products had no measurable radioactivity.

However, once the organism dies, the amount of carbon-14 steadily decreases.

By measuring the amount of carbon-14 left in the organism, it's possible to work out how old it is.