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carbon 12
noun
: an isotope of carbon of mass number 12 that is the most abundant carbon isotope and is used as a standard for measurements of atomic weight
Examples of carbon 12 in a Sentence
Recent Examples on the Web
Most carbon exists in the stable form of carbon 12.
—James Shreeve, Discover Magazine, 11 Nov. 2019
Scientists can look at the amount of carbon 12 and--based on the ratio-- deduce how much carbon 14 was originally present.
—James Shreeve, Discover Magazine, 11 Nov. 2019
Measuring the extent to which multiple carbon 13 atoms (a rare, stable form of carbon with an extra neutron) replace carbon 12 (the most common form of carbon) in a particular molecule, for instance, can tell researchers about the temperature when the compound formed.
—Clara Moskowitz, Scientific American, 15 June 2023
Carbon has two stable isotopes, measured as either carbon 12 or carbon 13.
—Ashley Strickland, CNN, 17 Jan. 2022
But if Perseverance’s sample is found to contain not only methane but methane rich in an isotope called carbon 12, that could change.
—Jonathan O'Callaghan, Scientific American, 10 Nov. 2021
So researchers compare the amount of carbon 14 with the levels of carbon 12 and carbon 13 to determine how much time has passed since an organism perished.
—Scott Hershberger, Scientific American, 4 Aug. 2020
Chemically, carbon 14 behaves exactly like its stable siblings (carbon 12 and carbon 13), allowing plants to absorb it during photosynthesis and then pass it up the food chain.
—Scott Hershberger, Scientific American, 4 Aug. 2020
By controlling the magnetic field and other conditions inside the cannon, the researchers cause the carbon 14 atoms to veer away from the carbon 12 atoms and other elements.
—Carl Zimmer, The Atlantic, 20 Mar. 2020
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Word History
First Known Use
1936, in the meaning defined above
Dictionary Entries Near carbon 12
Cite this Entry
“Carbon 12.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/carbon%2012. Accessed 22 Dec. 2024.
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