the isotopic carbon atom that comprises 99 percent of naturally occurring carbon, and that since 1961 has been used as the standard for atomic weight by representing a unit of 12.00000.
A stable isotope of carbon, having six protons and six neutrons in the nucleus. Carbon 12 makes up most naturally occurring carbon.
the stable isotope of carbon having an atomic mass number 13, used as a tracer.
radiocarbon (def 1). Historical Examples The case of carbon-14 is an example of a permanent man-made modification of the environment. Atoms, Nature, and Man Neal O. Hines carbon 14 A naturally occurring radioactive isotope of carbon having six protons and eight neutrons in the nucleus. Carbon 14 is important in dating archaeological and biological remains […]
- Carbon-14 dating
an electric arc between two carbon electrodes, used mainly for lighting, as in an arc light for a motion-picture projector, or for intense heating, as in the cutting and welding of metals. Historical Examples After many experiments with platinum, he abandoned that material in favor of the carbon-arc in vacuo. Notable Events of the Nineteenth […]