# Argon radioactive dating

Radioactive decay allows geologists and physicists to measure the age of ancient fossils, rocks and even the Earth.

This process is called radiometric or radioactive dating.

Two situations where we can do this involve Potassium-40 atoms and Carbon-14 atoms.

All radioactive atoms decay to become a more stable kind of atom.

To see how we actually use this information to date rocks, consider the following: Usually, we know the amount, N, of an isotope present today, and the amount of a daughter element produced by decay, D*.

By definition, D* = N-1) (2) Now we can calculate the age if we know the number of daughter atoms produced by decay, D* and the number of parent atoms now present, N.

The only problem is that we only know the number of daughter atoms now present, and some of those may have been present prior to the start of our clock. The reason for this is that Rb has become distributed unequally through the Earth over time.

It is not as well publicized as its larger close neighbour MT Ruapehu, which has erupted briefly several times in the last five years.those that form during chemical reactions without breaking down).The unstable or more commonly known radioactive isotopes break down by radioactive decay into other isotopes.Radiometric dating is possible because the radioactive decay of large numbers of radioactive atoms follows a predictable pattern.This predictability allows scientists to measure the age of an object if they can work out how many radioactive atoms were originally present.