Question

What is carbon dating? How it is used to determine the age of fossils?

Answer 1

• Carbon dating is the process of determination of age of an organic matter from the relative proportions of carbon-12 and carbon-14 isotopes it contains.
• Carbon-14 is an isotope of carbon having 8 neutrons (two extra neutrons than carbon-12). This makes it heavy and unstable. Thus after thousands of years, it will eventually split down.
• Plants take carbon dioxide for photosynthesis and animals get this in their body by consuming plants.
• Also through respiration carbon dioxide gets back to the atmosphere.There is an equilibrium maintained throughout, but once a living thing dies, there is no further intake of food and no longer respiration. Therefore the carbon matter stays as it is.
• Slowly, radioactive decay starts in such bodies.
• The half-life of a radioactive element means the time taken for that particular element to half its quantity.
• Carbon-14 is a radioactive element, it has a half-life of 5730 years.
• Thus, by measuring the ratio of carbon-14 to carbon-12 left in that body and comparing that quantity to the carbon-14 half-life we can estimate the age of any fossil.