The isotope doesn't actually deteriorate; it just changes into something else.Isotopes decay at a constant rate known as the half-life.Within the nucleus, we find neutrons and protons; but for now, let's just focus on the neutrons.These neutrons can become unstable, and when they do, they release energy and undergo decay. Radioactivity occurs when the nucleus contains an excess amount of neutrons.
Elements occur naturally in the earth, and they can tell us a lot about our Earth's past.
Absolute age is just a fancy way of saying definitive or specific age as opposed to the relative age, which only refers to how old or young a substance is in comparison to something else.
To illustrate, let's use the isotope uranium-238, which has a half-life of 4.5 billion years.
Ever wonder how scientists concluded the age of the earth to be about 4.6 billion years old or how geologists determined the ages of caverns, rocks, volcanoes and the Himalayas? Well, scientists are able to answer all of these wondrous questions and more by use of a process called radiometric or radioactive dating.
Radioactive dating enables geologists to record the history of the earth and its events, such as the dinosaur era, within what they call the geologic time scale.