When ‘parent’ uranium-238 decays, for example, it produces subatomic particles, energy and ‘daughter’ lead-206.

Isotopes are important to geologists because each radioactive element decays at a constant rate, which is unique to that element.

Radiometric dating is often referred to as “radioactive dating” and “carbon dating,” though many different types of isotopes can be used to identify an object’s age.Contents: The half-life of a radioactive isotope is defined as the time it takes half of a sample of the element to decay.A mathematical formula can be used to calculate the half-life from the number of breakdowns per second in a sample of the isotope.When I first got involved in the creationism/evolution controversy, back in early 1995, I looked around for an article or book that explained radiometric dating in a way that nonscientists could understand. Young-Earth creationists -- that is, creationists who believe that Earth is no more than 10,000 years old -- are fond of attacking radiometric dating methods as being full of inaccuracies and riddled with sources of error. All these methods point to Earth being very, very old -- several billions of years old.The discovery gave scientists a tool for dating rocks that contain radioactive elements.Many elements have naturally occurring isotopes, varieties of the element that have different numbers of neutrons in the nucleus.This works because elements have a life cycle known as a “half-life.” A half-life refers to the amount of time it takes for an isotope to lose half of its atoms as a result of decaying.When an isotope decays, it often becomes a different kind of element altogether.Some isotopes have very long half-lives, measured in billions or even trillions of years.Others have extremely short half-lives, measured in tenths or hundredths of a second.This is different to relative dating, which only puts geological events in time Most absolute dates for rocks are obtained with radiometric methods.These use radioactive minerals in rocks as geological clocks.Geologists often need to know the age of material that they find.