# How does radioactive dating help determine the age of fossils

When the isotope is halfway to that point, it has reached its half-life.There are different methods of radiometric dating that will vary due to the type of material that is being dated.Uranium is not the only isotope that can be used to date rocks; we do see additional methods of radiometric dating based on the decay of different isotopes.For example, with potassium-argon dating, we can tell the age of materials that contain potassium because we know that potassium-40 decays into argon-40 with a half-life of 1.3 billion years.Radiocarbon dating, also known as carbon-14 dating or simply carbon dating, is a method used to determine the age of organic material by measuring the radioactivity of its carbon content.So, radiocarbon dating can be used to find the age of things that were once alive, like the Iceman.As a member, you'll also get unlimited access to over 70,000 lessons in math, English, science, history, and more.

Carbon-14 combines with oxygen to create carbon dioxide.

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.

The thing that makes this decay process so valuable for determining the age of an object is that each radioactive isotope decays at its own fixed rate, which is expressed in terms of its half-life.

These differing rates of decay help make uranium-lead dating one of the most reliable methods of radiometric dating because they provide two different decay clocks.

This provides a built-in cross-check to more accurately determine the age of the sample.

However, rocks and other objects in nature do not give off such obvious clues about how long they have been around.