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.
Some things you'll be assessed on include which radioisotope of carbon is used in carbon dating, the length of the half-life of carbon-14, and what you can determine about isotopes based upon half-life.
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.
After it forms, carbon-14 naturally decomposes, with a half-life of 5,730 years, through beta-particle decay.
It is often used on valuable artwork to confirm authenticity.
Each radioactive isotope decays by a fixed amount, and this amount is called the half-life.
The half-life is the time required for half of the original sample of radioactive nuclei to decay.
Once they die, they stop taking in carbon-14, and the amount present starts to decrease at a constant half-life rate.
Then the radiocarbon dating measures remaining radioactivity.