What is Carbon Dating? - Chemistry for Kids | Mocomi
There are some carbon particles in the atmosphere. When the sun's rays reach them, a few of these particles turn into carbon 14 (a radioactive carbon). Radioactive carbon decays at a known rate. This allows scientists to look at the amount of decay in a fossil's radioactive carbon and determine a relative date. The amount of carbon in the air has stayed the same for thousands of years. There is a small amount of radioactive carbon in all living organisms because .
At high geomagnetic latitudes, the carbon spreads evenly throughout the atmosphere and reacts with oxygen to form carbon dioxide.Using M & M's to Demonstrate Radiometric Dating
Carbon dioxide also permeates the oceansdissolving in the water. Plants take in atmospheric carbon dioxide by photosynthesis, and are ingested by animals. So, every living thing is constantly exchanging carbon with its environment as long as it lives.
Once a being dies, however, this exchange stops. The carbon in its body will remain until it decomposes or fossilizes.
The amount of carbon gradually decreases through radioactive beta decay with a half-life of 5, years. So, scientists can estimate the age of the fossil by looking at the level of decay in its radioactive carbon.
What is half life? Some chemical elements have more than one type of atom.
Radiometric dating Facts for Kids
Isotopes are different atoms of the same element. Carbon has two stable, nonradioactive isotopes: In addition, there are trace amounts of the unstable isotope carbon 14C on Earth. Carbon has a relatively short half-life of years, meaning that the amount of carbon in a sample is halved over the course of years due to radioactive decay.
Plants take up atmospheric carbon dioxide by photosynthesisand are eaten by animals, so every living thing is constantly exchanging carbon with its environment as long as it lives.
Once it dies, however, this exchange stops. In Hessel de Vries showed that the concentration of carbon in the atmosphere varies with time and locality.
The relatively short-lived 14C is constantly renewed by cosmic ray bombardment on atmospheric nitrogen. Since the bombardment is slightly variable, and for other reasons, the 14C taken into organic matter is also slightly variable. That leads to errors in the chronology.
However, under about 20, years the results can be compared with dendrochronologybased on tree rings. For the most accurate work, variations are compensated by means of calibration curves.
The method was developed by Willard Libby and his colleagues at the University of Chicago in Inhe was awarded the Nobel Prize in Chemistry for this work. He first demonstrated the accuracy of radiocarbon dating by accurately estimating the age of wood from an ancient Egyptian royal barge of which the age was known from historical documents.