carbon 13
noun
: an isotope of carbon of mass number 13 that constitutes about ¹/₇₀ of natural carbon and is used as a tracer especially in spectroscopy utilizing nuclear magnetic resonance
Examples of carbon 13 in a Sentence
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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
These isotopes, carbon 13 and oxygen 18, bond to each other more when the temperature is cooler, a handy relationship that geophysicists have been using to study Earth's past climate in the geological record.
—Veronique Greenwood, Discover Magazine, 24 June 2011
Blue = winter and low carbon 13/low bone cell density.
—Jennifer Ouellette, Ars Technica, 23 Feb. 2022
Yellow = summer and high carbon 13/high bone density.
—Jennifer Ouellette, Ars Technica, 23 Feb. 2022
Carbon has two stable isotopes, measured as either carbon 12 or carbon 13.
—Ashley Strickland, CNN, 17 Jan. 2022
Recent separate findings indicate that plant leaves receiving more light have a higher density of veins, as well as a higher ratio of a naturally occurring isotope called carbon 13.
—Rachel Nuwer, Scientific American, 1 Apr. 2021
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
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
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Clara Moskowitz, Scientific American, 15 June 2023
These isotopes, carbon 13 and oxygen 18, bond to each other more when the temperature is cooler, a handy relationship that geophysicists have been using to study Earth's past climate in the geological record.
—Veronique Greenwood, Discover Magazine, 24 June 2011
Blue = winter and low carbon 13/low bone cell density.
—Jennifer Ouellette, Ars Technica, 23 Feb. 2022
Yellow = summer and high carbon 13/high bone density.
—Jennifer Ouellette, Ars Technica, 23 Feb. 2022
Carbon has two stable isotopes, measured as either carbon 12 or carbon 13.
—Ashley Strickland, CNN, 17 Jan. 2022
Recent separate findings indicate that plant leaves receiving more light have a higher density of veins, as well as a higher ratio of a naturally occurring isotope called carbon 13.
—Rachel Nuwer, Scientific American, 1 Apr. 2021
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
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
Cite this Entry
“Carbon 13.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/carbon%2013. Accessed 3 Jul. 2025.
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