5056 Carbon-14 Carbon-14, 14C, or radiocarbon, is a radioactive isotope of carbon with a nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples. Carbon-14 was discovered on 27 February 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, although its existence had been suggested by Franz Kurie in 1934. 14762-75-5 26873 CH4 Ingestion, inhalation, puncture, wound, skin contamination (absorption) Internalized radionuclides that emit β particles are carcinogenic to humans (Group 1) (L2150). Carbon-14 undergoes beta decay. 2014-10-15T22:07:58Z 2014-12-24T20:27:02Z true [14CH4] CH4 InChI=1S/CH4/h1H4/i1+2 InChIKey=VNWKTOKETHGBQD-NJFSPNSNSA-N 18.035 18.034542116 Exogenous Solid 25031