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.
So, we start out with two isotopes of uranium that are unstable and radioactive.
They release radiation until they eventually become stable isotopes of lead.
These two uranium isotopes decay at different rates. The half-life of the uranium-238 to lead-206 is 4.47 billion years.
The uranium-235 to lead-207 decay series is marked by a half-life of 704 million years.
Radiometric dating is used to estimate the age of rocks and other objects based on the fixed decay rate of radioactive isotopes.
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.
As soon as a living organism dies, it stops taking in new carbon.
The ratio of carbon-12 to carbon-14 at the moment of death is the same as every other living thing, but the carbon-14 decays and is not replaced.
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.
C and counting the amount of each) allows one to date the death of the once-living things.