This causes them to give off their stored energy in the form of light impulses (photons). A similar effect can be brought about by stimulating the sample with infrared light.
The intensity of thermoluminescence is directly related to the amount of accumulated changes produced by background radiation, which, in turn, varies with the age of the sample and the amount of trace radioactive elements it contains..
The atoms of crystalline solids, such as pottery and rock, can be altered by this radiation.
This dating method can be used with samples that are as young as a few decades to as old as the earth and beyond.
decay or the rate of other cumulative changes in atoms resulting from radioactivity. The various isotopes of the same element differ in terms of atomic mass but have the same atomic number..
One half-life is the amount of time required for of the original atoms in a sample to decay.
As a result, all of the argon-40 in a volcanic rock sample is assumed to date from that time.
When a fossil is sandwiched between two such volcanic deposits, their potassium-argon dates provide a minimum and maximum age.