Radiocarbon dating is based on the property that the activity concentration of 14C in dead tissues can be used to calculate the time that has elapsed since death occurred. More details Reporting time At present (September 2017) it takes ca 3 months (excluding periods when the laboratory is closed for holidays) from the arrival of a sample until we report the result to the customer.
Since each beta particle represents one decayed carbon-14 atom, we know how many carbon-14 atoms decayed during that month.
Chemists have already determined how many atoms are in a given mass of each element, such as carbon.4 So if we weigh a lump of carbon, we can calculate how many carbon atoms are in it.
And as far as we know, it has been forming in the earth’s upper atmosphere at least since the Fall, after the atmosphere was made back on Day Two of creation week (part of the expanse, or firmament, described in Genesis 1:6–8). Cosmic rays from outer space are continually bombarding the upper atmosphere of the earth, producing fast-moving neutrons (sub-atomic particles carrying no electric charge) (figure 1).1 These fast-moving neutrons collide with nitrogen-14 atoms, the most abundant element in the upper atmosphere, converting them into radiocarbon (carbon-14) atoms.
Since the atmosphere is composed of about 78 percent nitrogen,2 a lot of radiocarbon atoms are produced—in total about 16.5 lbs. These rapidly combine with oxygen atoms (the second most abundant element in the atmosphere, at 21 percent) to form carbon dioxide (CO This carbon dioxide, now radioactive with carbon-14, is otherwise chemically indistinguishable from the normal carbon dioxide in the atmosphere, which is slightly lighter because it contains normal carbon-12.
Laboratory staff, from left: Mats Rundgren (lecturer), Raimund Muscheler (professor), Anne Birgitte Nielsen (lecturer), Ingemar Hansson (research engineer), Mattias Olsson (research engineer), Göran Skog (lecturer) and Git Klintvik Ahlberg (technician).