Carbon-14 is a radioisotope of the chemical element carbon, which has 8 neutrons in its atomic nucleus in addition to the element-specific 6 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 14.
See also: List of individual Carbon isotopes (and general data sources).
General data
Name of the isotope:Carbon-14; C-14Other names:Radiokohlenstoff. RadiocarbonSymbol:14C or 146CMass number A:14 (= number of nucleons)Atomic number Z:6 (= number of protons)Neutrons N:8Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.3333333333333 (= neutron-proton ratio)Neutron excess (N-Z):2Isotopic mass:14.003241988(4) u (atomic weight of Carbon-14)Nuclide mass:13.9999505 u (calculated nuclear mass without electrons)Mass excess:3.01989 MeVMass defect:0.113027532 u (per nucleus)Nuclear binding energy:105.28446789 MeV (per nucleus) 7.52031914 MeV (average binding energy per nucleon)Separation energy:SN = 8.176433(4) MeV (first neutron) SP = 20.831(1) MeV (first proton)Half-life:5700(30) yearsDecay constant λ:3.853504888825 × 10-12 s-1Specific activity α:165721258546.73 Bq g-1 4.4789529336954 Ci g-1Spin and parity: (nuclear angular momentum)0+Isobaric spin: 1Quadrupole moment Q:+0.02044(3) barn (100 fm2)Charge radius:2.5025(87) femtometer fmMirror nucleus:Oxygen-14Year of discovery:1936
Radioactive Decay
Carbon-14 undergoes beta decay with emission of an electron and an electron antineutrino:
14C → 14N + e- + ve + 156.476 keV.
The decay product is the stable nuclide Nitrogen-14.
Half-life T½ = 5700(30) years respectively 1.79874478055 × 1011 seconds s.
Comparison of the natural Carbon isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):
Atomic Mass ma
Quantity
Half-life
Spin
Carbon Isotopic mixture
12.011 u
100 %
Isotope 12C
12.00000000000 u
98.94 % [98.84 - 99.04 %]
stable
0+
Isotope 14C
14.003241988(4) u
[trace]
5700(30) years
0+
Isotope 13C
13.003354835(2) u
1.06 % [0.96 - 1.16 %]
stable
1/2-
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 8) and isobaric (same nucleon number A = 14) with Carbon-14. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
