carbon 12


Definition of carbon 12

: 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 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 The key is in the rock’s atomic composition; organisms that use sunlight for energy incorporate a lighter version of carbon, called carbon 12, over the heavier carbon 13. Peter Byrne, Quanta Magazine, 24 Apr. 2014

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'carbon 12.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of carbon 12

1936, in the meaning defined above

Learn More About carbon 12

Time Traveler for carbon 12

Time Traveler

The first known use of carbon 12 was in 1936

See more words from the same year

Dictionary Entries Near carbon 12


carbon 12

carbon 13

See More Nearby Entries 

Statistics for carbon 12

Cite this Entry

“Carbon 12.” Dictionary, Merriam-Webster, Accessed 17 Jan. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon


Test Your Vocabulary

Difficult Spelling Words Quiz

  • alphabet pasta spelling help
  • Which is the correct spelling?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!