Uploaded June 2019 | Updated September 2026, 3 days ago
This video explains the carbon-14 method for determining the age of an object containing organic material by using the properties of this radioactive isotope of carbon.
Carbon has two stable non-radioactive isotopes, carbon-12 and carbon-13, and one radioactive isotope, carbon-14. The half-life of carbon-14 is 5730 years. Because of its relatively short half-life you might expect that its concentration in the atmosphere would be reduced over thousands of years but new carbon-14 is always being produced in the upper atmosphere by the interaction of cosmic rays, neutrons and nitrogen-14 atoms. Therefore the concentration of carbon-14 in the atmosphere is relatively constant.
Plants and animals have the same concentration of carbon-14 as the atmosphere because they are constantly exchanging it with their environment. When they die, the carbon-14 in their bodies continues to decay, but they are no longer able to take up new carbon-14 and the concentration of carbon-14 in their bodies decreases. Knowing the concentration of carbon-14 at the time of death and the concentration of carbon-14 some time (t) after death enables you to determine how long it has been since the plant or animal died.
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This video explains the carbon-14 method for determining the age of an object containing organic material by using the properties of this radioactive isotope of carbon.
Carbon has two stable non-radioactive isotopes, carbon-12 and carbon-13, and one radioactive isotope, carbon-14. The half-life of carbon-14 is 5730 years. Because of its relatively short half-life you might expect that its concentration in the atmosphere would be reduced over thousands of years but new carbon-14 is always being produced in the upper atmosphere by the interaction of cosmic rays, neutrons and nitrogen-14 atoms. Therefore the concentration of carbon-14 in the atmosphere is relatively constant.
Plants and animals have the same concentration of carbon-14 as the atmosphere because they are constantly exchanging it with their environment. When they die, the carbon-14 in their bodies continues to decay, but they are no longer able to take up new carbon-14 and the concentration of carbon-14 in their bodies decreases. Knowing the concentration of carbon-14 at the time of death and the concentration of carbon-14 some time (t) after death enables you to determine how long it has been since the plant or animal died.
Social Media for Step by Step Science:
Teacher Pay Teachers Store: tinyurl.com/y6d2cdfj
Instagram: instagram.com/stepbystepscience101
Website: stepbystepscience.com
Blog: stepbystepscience.com/blog
Link Tree: https://linktr.ee/stepbystepscience
This video can be shared at youtu.be/uwNaPvgt4K8
Please support my channel by doing all of the following:
(1) Subscribe, get all my physics, chemistry and math videos.
(2) Give me a thumbs up for this video.
(3) Leave me a nice positive comment.
(4) Sharing is Caring, sharing this video with all of your friends.
