What is uranium 238 used for dating rocks Chat with sexing couple

08 May

Carbon 14 with a half life of 5,700 years can only be used to date fossils of approximately 50,000 years. If 50% of pure uranium' is left in a sample the sample is assumed to be 4.5 billion years old.( This is assuming that the original sample was 100% uranium and no Uranium 238 has been eroded or lost in 4.5 billion years old.

Most fossils are thought to be much older than 50,000 years. The fossilized remains have been mineralized where the original organic material has been replaced and turned into stones containing no carbon. If a fossil has only 25 % of the Uranium 238 the sample has an estimated age of 3.2 Billion years.

Some of the isotopes used for this purpose are uranium-238, uranium-235 and potassium-40, each of which has a half-life of more than a million years.

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.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.This means all living things have radioactive carbon-14 in them.When an organism, eg a tree, dies it stops taking in carbon dioxide.