How does radioactive dating help determine the age of fossils updating nvidia drivers in vista
Scientists discovered that rocks could be timepieces -- literally.
Many chemical elements in rock exist in a number of slightly different forms, known as isotopes.
By measuring the ratio of the amount of the original radioactive element to the daughter isotope, scientists can determine how many half-lives the element has undergone and from there can figure out the absolute age of the sample.
The half-lives of several radioactive isotopes are known and are used often to figure out the age of newly found fossils.
Using this technique, called radiometric dating, scientists are able to "see" back in time.
Perhaps the most widely used evidence for the Theory of Evolution through Natural Selection is the fossil record.
There are several reasons why, but the main reasons is that Carbon-14 is a naturally occurring isotope in all forms of life and its half-life is about 5730 years, so we are able to use it to date more "recent" forms of life relative to the Geologic Time Scale.
After all, the ever-changing Earth rarely left a complete geological record.For example, about 1.5 percent of a quantity of Uranium 238 will decay to lead every 100 million years.By measuring the ratio of lead to uranium in a rock sample, its age can be determined.Certain isotopes are unstable and undergo a process of radioactive decay, slowly and steadily transforming, molecule by molecule, into a different isotope.This rate of decay is constant for a given isotope, and the time it takes for one-half of a particular isotope to decay is its radioactive half-life.