BASIS OF RADIOCARBON DATING Radiocarbon dating compares the amount of normal carbon with the amount of radioactive carbon in a sample.
If we know what the original ratios of C14 to C12 were in the organism when it died, and if we know that the sample has not been contaminated by contact with other carbon since its death, we should be able to calculate when it died by its C14 to C12 ratio.Aboveground nuclear testing almost doubled the amount of carbon-14 in the atmosphere. The black arrow shows when the Partial Test Ban Treaty was enacted that banned aboveground nuclear tests. A special kind of radiocarbon dating: Bomb radiocarbon dating.As we mentioned above, the carbon-14 to carbon-12 ratio in the atmosphere remains nearly constant. Basis of Radiocarbon Dating Problems with Radiocarbon Dating The Earth's Magnetic Field Table 1 Effect of Increasing Earth's Magnetic Field Removal of Carbon From the Biosphere Water Vapour Canopy Effect on Radiocarbon Dating Figure 1 Apparent Radiocarbon Dates Heartwood and Frozen Time Early Post-Flood Trees Appendix Radiocarbon Date Table HOW ACCURATE IS RADIOCARBON DATING? The normal carbon atom has six protons and six neutrons in its nucleus, giving a total atomic mass of 12.Radiocarbon dating is frequently used to date ancient human settlements or tools. It is a stable atom that will not change its atomic mass under normal circumstances.However, because it has too many neutrons for the number of protons it contains, it is not a stable atom.Every 5,730 years, approximately half of this radioactive carbon spontaneously converts itself back into nitrogen by emitting an electron from a neutron.Radioactive carbon (Carbon 14) is formed in the upper atmosphere as a byproduct of cosmic radiation.Cosmic rays are positively charged atoms moving at enormous speeds.The radioactive carbon has six protons and eight neutrons in its nucleus, giving it a total atomic mass of 14.This atom is not stable, and will break down, releasing nuclear energy in the process.