Depreciation carbon dating
Depending on the isotope, its Half Life may range from a few fractions of a second to several billion years. The Half Life of Uranium-238 is 4,500,000,000 years.There is even a radioactive isotope of carbon, carbon-14. C-14 has two extra neutrons and a half-life of 5730 years.
It is necessary that the dating sample be as uncontaminated as possible, to give it an accurate age.
The impact of this technique on the world of science, led to Libby being awarded the Nobel prize in chemistry, in 1960.
This dating method is based on comparison of ratios of two carbon isotopes, which are C-12 and C-14. Isotopes are elements with the same atomic number, but different atomic mass numbers. By comparing the amount of radioactive carbon present now, with the amount at the beginning, an age estimate can be made, based on laws of radioactive decay.
The Half Life is independent of the physical state (solid, liquid, gas) temperature, pressure, the chemical compound in which the nucleus finds itself, and essentially any other outside influence.
It is independent of the chemistry of the atomic surface, and independent of the ordinary physical factors of the outside world.