Radioactive dating u 238
This method is also very limited because uranium is not found in every old rock.
It is rarely found in sedimentary or metamorphic rocks, and is not found in all igneous rocks.
There are several methods of determining the actual or relative age of the earth's crust: examination of fossil remains of plants and animals, relating the magnetic field of ancient days to the current magnetic field of the earth, and examination of artifacts from past civilizations.
However, one of the most widely used and accepted method is radioactive dating.
In 1907, the American chemist Bertram Boltwood demonstrated that he could determine the age of a rock containing uranium-238 and thereby proved to the scientific community that radioactive dating was a reliable method.
Uranium-238, whose half-life is 4.5 billion years, transmutes into lead-206, a stable end-product.
Some beta particles are capable of penetrating the skin and causing damage such as skin burns.For example, the decay chain that begins with Uranium-238 culminates in Lead-206, after forming intermediates such as Uranium-234, Thorium-230, Radium-226, and Radon-222. Only the final, stable atom in the chain is not radioactive.Some decay products are a different chemical element.Perhaps the best method for dating rocks is the potassium-40/argon-40 method.Potassium is a very common mineral and is found in sedimentary, metamorphic, and igneous rock.
Elements that emit ionizing radiation are called radionuclides.