Notable Isotopes 
12C [6 neutrons]
Abundance: 98.93%
Stable with 6 neutrons
| In 1961 the International Union of Pure and Applied Chemistry (IUPAC) adopted the isotope carbon-12 as the basis for atomic weights. |
13C [7 neutrons]Abundance: 1.07%
Stable with 7 neutrons
14C [8 neutrons]Abundance: trace
Half life: 5730 years [ beta- ]
Decay Energy: 0.156 MeVDecays to 14N.
| A radioactive isotope, discovered February 27th 1940, by Martin Kamen and Sam Ruben. |
| Its presence in organic materials is used in radiocarbon dating. It occurs naturally and has a relative abundance up to 1 part per trillion (0.0000000001%) of all naturally-occurring carbon on Earth. |