Note that, contrary to a popular misconception, carbon dating is not used to date rocks at millions of years old.Before we get into the details of how radiometric dating methods are used, we need to review some preliminary concepts from chemistry.Assumptions in the scientific community are extremely important.
Carbon-14 is mostly used to date once-living things (organic material). Carbon-14 is constantly being added to the atmosphere.
The atomic number corresponds to the number of protons in an atom.
Atomic mass is a combination of the number of protons and neutrons in the nucleus.
There are two main applications for radiometric dating.
One is for potentially dating fossils (once-living things) using carbon-14 dating, and the other is for dating rocks and the age of the earth using uranium, potassium and other radioactive atoms.