Carbon dating uses the radioactive isotope carbon-14 to determine the age of organic materials. The document outlines the history, principles, applications, and limitations of carbon dating. Specifically, it notes that carbon-14 is formed in the atmosphere and incorporated into living things, but after death the amount of carbon-14 decays at a known rate, allowing the age of a sample to be estimated by measuring its remaining carbon-14. Examples are given of carbon dating being used to determine the ages of artifacts such as ancient manuscripts, cave paintings, and archaeological sites.

1. Carbon Dating
Presented by,
Jyoti Patel
1st Sem M.Sc Botony
Dos in Molecular Biology Guided by,
MS

2. Content
• Introduction
• History
• Carbon Dating.
• Principle of carbon dating.
• Life Cycle of Carbon 14
• Application
• Limitation
• Summary

3. INTRODUCTION
• All carbon atoms have 6 protons in the nucleus, but the nucleus may
also contains 6, 7 or 8 neutrons.
• There are 3 naturally occurring isotopes of carbon on earth,
1. Carbon-12 : Stable nucleus ( 99% of all natural carbon)
2. Carbon-13 : Stable nucleus (1%)
3. Carbon-14 : unstable radioactive isotopes ( Where 1 in 10 carbon atoms
in the atmosphere is C-14)

5. History
• The Carbon-14 method was developed by the
American physicist Willard Frank Libby and
his team in 1946 at the University of Chicago.
• He determined the half life to be 5568 years ±
30 years and it is popularly known as Libby
half life.
• This half life has later been re-determined by
Godwin as 5730 ±40 years which is known as
the Cambridge Half Life.
• In 1960, Mr. Willard F. Libby was awarded
the Nobel Prize in Chemistry in recognition of
his efforts to develop radiocarbon dating.

6. Carbon dating
It is one of the form of Radiometric dating and also referred as
Radiocarbon dating or Carbon-14 dating.
• This method is used for determining the age of an object containing
organic material by using the properties of radiocarbon, a radioactive
isotopes of carbon.

7. Principle
• Carbon 14 is continually being formed in the upper atmosphere by the
effect of cosmic ray neutrons on nitrogen 14 atoms. It is rapidly
oxidized in air to form carbon dioxide and enters the global carbon
cycle.
• Plants and animals assimilate carbon 14 from carbon dioxide
throughout their lifetimes. When they die, they stop exchanging
carbon with the biosphere and their carbon 14 content then starts to
decrease at a rate determined by the law of radioactive decay.
• Radiocarbon dating is essentially a method designed to measure
residual radioactivity.

9. Continued….
• Animal get their C-14 dose from the food that they consume.
• When the organism (or a tissue) dies absorption of C-14 ceases and the
amount of C-14 gradually decays.
• The half-life of the decay of C-14 to nitrogen is 5730 years so the
concentration halves every 5730 years.
• HALF-LIFE: The time taken for half a radioactive sample to decay
into something else.
• Radioactive carbon ( C-14) β decays to nitrogen (N14) by emitting an
electron (e-) and an antineutrino (v-) with no mass or charge.

11. Application
• Carbon dating is useful to archeologists when they need to know the
approximate date of a fossil or any other object.
• Carbon dating is used to find the ages of Trees, Mummies, Fossils, or
other organic material.
• Carbon-14 is used to study the passage of carbon dating
photosynthesis in plants.

12. Continued….
• Radiocarbon dating of sacred mummies from ancient Egypt.
• Radiocarbon dating can be used to date carbon containing pigment like
charcoal, it was even useful in dating cave paintings.
• Samples that have been radiocarbon dated since the inception of the
method include,
• Charcoal, wood, twigs, seeds, bones, shells, leather, peat.
• Lake mud, soil, hair, pottery, pollen.
• Wall paintings, corals, blood residues, fabrics.
• Paper or parchment, resins, and water.

13. Continued…
Ancient Quran Manuscript
(15,00 years old)
Ancient ink : Iceman has world’s
oldest tattoos ( Chinchoro mummy)
(15,00 years old)

14. Continued…
Burial site with items dug up from the
Sanauli site in Baghpa
(3800 Years Old)
Prehistoric horse decorates the walls of Lascaux
Cave in France
(40,000 BC to 8000 BC)

15. Limitation
• This technique used only for dating organic material.
• Maximum age limit fir C-14 dating is 52,000 to 62,000 years.
• Several physical, chemical, and biological processes can cause
contamination.
• Carbon exchange between the sample and the atmosphere is a
common cause of contamination in bone, wood and shell samples.

16. Summary
• C-14 method is used for determining the age of an object containing
organic material by using the properties of radiocarbon, a radioactive
isotope of carbon.
• The half-life of the decay of C-14 to nitrogen 14 is 5730 years so the
concentration halves every 5730 years.
• When the organism ( or tissue) dies absorption of C-14 ceases and the
amount of C-14 gradually decays in every half life.
• Carbon dating is used to find the age of Trees, Mummies, Fossils, or
others organic materials.

17. Thank You!
Queries are welcome…
-JyotiPatel