What is Carbon 14 Dating

Carbon is one of the most common elements on earth which is a fundamental building block of life. Carbon also has various forms made with different kinds of isotopes of itself. Some of the most common are Carbon-12 which is commonly found in plant life like trees, Carbon-13 produced by in volcanic smoke, and Carbon-14 formed in the atmosphere by the interaction of cosmic rays and atmospheric Nitrogen.

In 1948, American chemist Willard Libby discovered a way to use this unstable carbon isotope to date old objects and organic tissues. Libby would later win a Nobel Peace Prize for the technique he discovered called carbon-14 dating.

What is Carbon 14 Dating

Carbon dating, also known as radiocarbon dating, is a method employed by scientists to determine the age of organic materials based on the decay of Carbon-14. Carbon-14 (C-14) is a radioactive isotope of carbon, with a nucleus containing six protons and eight neutrons.

Living organisms continuously absorb carbon, and while they are alive, the ratio of Carbon-14 to Carbon-12 remains relatively constant. When an organism dies the C14 within that animal’s body would start to decrease at a fixed rate and cease to absorb new carbon.

The Carbon-14 within its remains starts to decay which scientists use to determine the elapsed time since death. With carbon dating, a scientist can determine how old a specimen is by studying the amount of C14 within the sample.

Scientists use a technique called liquid scintillation counting or accelerator mass spectrometry to measure the remaining Carbon-14 in a sample. By comparing the initial and remaining Carbon-14 levels, they can calculate the time that has passed since the organism’s demise.

Carbon 14 has a half-life of about 5,730 years and carbon dating as a method can only date up to 60,000 years to the past. The amount of carbon-14 is sometimes not enough to accurately determine the age of a remain or object accurately.

Can you use C-14 dating to know the age of a fossil?

As long as the fossil is not older than 60,000 years, it can still help determine the age of the fossil. For much older fossils, Stratigraphy is one of the most common ways to determine the age of a fossil. Stratigraphy is the study of strata or layers of soil in a particular place. Each layer of earth has come from different periods of the Earth’s life.

References:

• Radiocarbon Dating – American Chemical Society
• What is Carbon Dating? | University of Chicago News
• 18.5D: Carbon Dating and Estimating Fossil Age – Biology LibreTexts

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