Radiocarbon dating may only be used on organic materials.
Typically (6): The above list is not exhaustive; most organic material is suitable so long as it is of sufficient age and has not mineralised - dinosaur bones are out as they no longer have any carbon left.
The decay rate of radioactive elements is described in terms of half-life.
The half-life of an atom is the amount of time it takes for half of the atoms in a sample to decay.
Potassium-40 is another radioactive element naturally found in your body and has a half-life of 1.3 billion years.