Radiogenic dating methods
When a life form is alive and undergoing some sort of respiration, it will be gaining C-14 at a relatively high rate (it will equilibrate with the C-14 in the atmosphere) and losing it to decay at a different rate.However, when the life form dies and is buried or otherwise stops interacting with atmospheric gases there will be no further increase in the amount of radioactive carbon in the system.While the overall method of Radiometric Dating is the same through each type, the specific isotopes that are used changes.
Like carbon, potassium has three natural isotopes, one of which is radioactive.
One of the primary decay products of K-40 is Ar-40--a stable and unreactive gas.
Potassium decay has been established as the only source of Argon in volcanic rocks; it is a gas so most of it escapes unless it is formed after the molten rock has solidified, and it is not a major product in any other reactions.
Carbon's most abundant and stable isotope has a mass of 12 (six protons and six neutrons).
However, there is also a neutron-rich radioactive isotope of carbon.