Learn about half-life and how it is used in different dating methods, such as uranium-lead dating and radiocarbon dating, in this video lesson. As we age, our hair turns gray, our skin wrinkles and our gait slows.
However, rocks and other objects in nature do not give off such obvious clues about how long they have been around.
The nucleus contains protons (tiny particles each with a single positive electric charge) and neutrons (particles without any electric charge).
Orbiting around the nucleus are electrons (tiny particles each with a single negative electric charge).
The carbon-14 it contained at the time of death decays over a long period of time.
By measuring the amount of carbon-14 left in dead organic material the approximate time since it died can be worked out.
There's a small amount of radioactive carbon-14 in all living organisms.
The methods work because radioactive elements are unstable, and they are always trying to move to a more stable state. This process by which an unstable atomic nucleus loses energy by releasing radiation is called radioactive decay.So, we rely on radiometric dating to calculate their ages.Radiometric dating, or radioactive dating as it is sometimes called, is a method used to date rocks and other objects based on the known decay rate of radioactive isotopes.This method is useful for igneous and metamorphic rocks, which cannot be dated by the stratigraphic correlation method used for sedimentary rocks. Some do not change with time and form stable isotopes (i.e.those that form during chemical reactions without breaking down).Each chemical element, such as carbon and oxygen, consists of atoms.