And radiocarbon dating
Libby estimated that the steady state radioactivity concentration of exchangeable carbon-14 would be about 14 disintegrations per minute (dpm) per gram.
In 1960, he was awarded the Nobel Prize in chemistry for this work.
By Kamil Erkan Libbys discovery, now known as the carbon-14 (or radiocarbon) technique, was a method that could be used to determine the age of organic remains.
The resulting radiocarbon combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire in a sample from a dead plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died.
The method was developed by Willard Libby in the late 1940s and soon became a standard tool for archaeologists.
Libby received the Nobel Prize in Chemistry for his work in 1960.
Today, archeologists and paleontologists employ this technique to determine the age of organic materials (bones, teeth, wood, etc.) that are less than fifty thousand years in age. The theory is simple: Cosmic particles coming from outer space continuously collide with stable carbon-12 atoms in CO2 molecules, which are widespread in the atmosphere.
Each carbon-12 atom takes up two neutrons and is converted into a radioactive carbon-14 atom.