Absolute dating of rocks and fossils Cams sex chat dairct
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 uranium-235 to lead-207 decay series is marked by a half-life of 704 million years.
Uranium is not the only isotope that can be used to date rocks; we do see additional methods of radiometric dating based on the decay of different isotopes.
For example, with potassium-argon dating, we can tell the age of materials that contain potassium because we know that potassium-40 decays into argon-40 with a half-life of 1.3 billion years.
With rubidium-strontium dating, we see that rubidium-87 decays into strontium-87 with a half-life of 50 billion years.
By anyone's standards, 50 billion years is a long time.