How is carbon-14 produced?
Cosmic rays enter the earth’s atmosphere in large numbers every day and when one collides with an atom in the atmosphere, it can create a secondary cosmic ray in the form of an energetic neutron. When these energetic neutrons collide with a nitrogen-14 (seven protons, seven neutrons) atom it turns into a carbon-14 atom (six protons, eight neutrons) and a hydrogen atom (one proton, zero neutrons). Since Nitrogen gas makes up about 78 percent of the Earth’s air, by volume, a considerable amount of Carbon-14 is produced. The carbon-14 atoms combine with oxygen to form carbon dioxide, which plants absorb naturally and incorporate into plant fibers by photosynthesis. Animals and people take in carbon-14 by eating the plants. The ratio of normal carbon (carbon-12) to carbon-14 in the air and in all living things at any given time is nearly constant. Maybe one in a trillion carbon atoms are carbon-14. Both Carbon-12 and Carbon-13 are stable, but Carbon-14 decays by very weak beta decay to nit
