Thus carbon-14 has six protons and eight neutrons.) Carbon-12 is by far the most abundant carbon isotope, and carbon-12 and -13 are both stable.
This age is obtained from radiometric dating and is assumed by evolutionists to provide a sufficiently long time-frame for Darwinian evolution.
Other corrections must be made to account for the proportion of throughout the biosphere (reservoir effects).
Additional complications come from the burning of fossil fuels such as coal and oil, and from the above-ground nuclear tests done in the 1950s and 1960s.
Carbon has an atomic number of 6, an atomic weight of 12.011, and has three isotopes: carbon-12, carbon-13, and carbon-14.
(The numbers 12, 13 and 14 refer to the total number of protons plus neutrons in the atom's nucleus.
The method was developed by Willard Libby in the late 1940s and soon became a standard tool for archaeologists.
Libby received the Nobel Prize in Chemistry for his work in 1960.
Since its introduction it has been used to date many well-known items, including samples of the Dead Sea Scrolls, enough Egyptian artifacts to supply a chronology of Dynastic Egypt, and Otzi the iceman.
Willard Libby at the University of Chicago developed the technique of radiocarbon dating in 1949.
The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen.
The resulting radiocarbon combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire in a sample from a dead plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died.