Atmospheric carbon-14 rapidly reacts with oxygen in air to form carbon dioxide and enters the carbon cycle.Plants take in carbon dioxide through photosynthesis and the carbon-14 makes its way up the food chain and into all living organisms.You might remember that it was mentioned earlier that the amount of carbon-14 in living things is the same as the atmosphere.
Free 5-day trial Ever wondered how scientists know the age of old bones in an ancient site or how old a scrap of linen is?
The technique used is called carbon dating, and in this lesson we will learn what this is and how it is used. Carbon dating, or radiocarbon dating, is a method used to date materials that once exchanged carbon dioxide with the atmosphere. In the late 1940s, an American physical chemist named Willard Libby first developed a method to measure radioactivity of carbon-14, a radioactive isotope.
Libby was awarded the Nobel Prize in chemistry for his work in 1960.
Carbon dioxide in the atmosphere contains a constant amount of carbon-14, and as long as an organism is living, the amount of carbon-14 inside it is the same as the atmosphere.
However, once the organism dies, the amount of carbon-14 steadily decreases.
By measuring the amount of carbon-14 left in the organism, it's possible to work out how old it is.Once the organism dies, the amount of carbon-14 reduces by the fixed half-life - or the time required for half of the original sample of radioactive nuclei to decay - of 5,730 years, and can be measured by scientists for up to 10 half-lives.Measuring the amount of radioactive carbon-14 remaining makes it possible to work out how old the artifact is, whether it's a fossilized skeleton or a magnificent piece of artwork.After viewing the video on carbon dating, use your newfound knowledge to: Did you know…We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities.Scientists often use the value of 10 half-lives to indicate when a radioactive isotope will be gone, or rather, when a very negligible amount is still left.