Different methods of radiometric dating can be used to estimate the age of a variety of natural and even man-made materials.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.The thing that makes this decay process so valuable for determining the age of an object is that each radioactive isotope decays at its own fixed rate, which is expressed in terms of its half-life.

dating the iceman-8dating the iceman-29

When they die no new carbon-14 is taken in by the dead organism.

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.

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.

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.

For example, in 1991, two hikers discovered a mummified man, preserved for centuries in the ice on an alpine mountain.

Later called Ötzi the Iceman, small samples from his body were carbon dated by scientists.

The results showed that Ötzi died over 5000 years ago, sometime between 33 BC. Uranium has a very long half-life and so by measuring how much uranium is left in a rock its approximate age can be worked out.

Radiometric dating is used to estimate the age of rocks and other objects based on the fixed decay rate of radioactive isotopes.