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LITHOEN

Isotope

Carbon-12

The dominant stable isotope of carbon and the reference against which carbon isotope ratios are reported.

Classification

element symbol
C
mass number
12
stability
stable

How this record is known

1
Directly recorded
Observed or measured, reported by the party that made the observation.
1
Settled consensus
Cited as the accepted position of the discipline.

2 of 2 claims on this page cite at least one registered source. Counts describe how each statement is known, not how likely it is to be true.

What Lithoen records

Each claim states how it is known and cites its evidence.

Measured0.9884–0.9904 ratio

CIAAW gives the representative abundance of carbon-12 in normal materials as the interval [0.9884, 0.9904], reflecting real variation between materials rather than measurement uncertainty.

  • method: Critical evaluation of published isotopic composition measurements by CIAAW.
  • precision note: An interval because the natural composition varies; not an uncertainty on a single value.

Evidence support: Supported by the cited evidence one source

Evidence: Commission on Isotopic Abundances and Atomic Weights (IUPAC) 2024 Primary authority

Established12 nucleons

Carbon 12 has mass number 12: 12 nucleons in the nucleus.

  • definition basis: The mass number identifies a nuclide within its element; the atomic number identifies the element.

Evidence support: Supported by the cited evidence one source

Evidence: Commission on Isotopic Abundances and Atomic Weights (IUPAC) 2024 Primary authority

In the knowledge graph

  • Carbon-12 is an isotope of Carbon

Record last updated 2026-09-06. Corrections follow the published corrections policy; superseded claims are retained, never silently edited.