carbon 13

American  

Also carbon-13

noun

1. the stable isotope of carbon having an atomic mass number 13, used as a tracer.

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Etymology

Origin of carbon 13

First recorded in 1940–45

Example Sentences

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.

From Scientific American

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.

From Scientific American

Carbon 13 usually comes from inorganic sources, such as volcanoes, while carbon 12 is tied to living things.

From Washington Times

There’s carbon 12 and its ever-so-slightly-heavier sibling, carbon 13.

From Washington Times

As far as Knauth is concerned, the simplest explanation for the fact that low levels of carbon 13, those geochemical ghosts of ancient photosynthesizers, coexist with cell-like microfossils is that there were massive amounts of life on land during the Precambrian.

From Scientific American