What isotopes are used for radioactive dating
The Wheeler Formation has been previously dated to approximately 507 million year old, so we know the trilobite is also about 507 million years old.
But, how can we determine how old a rock formation is, if it hasn’t previously been dated?
Most of the radioactive isotopes used for radioactive dating of rock samples have too many neutrons in the nucleus to be stable.
Recall that an isotope is a particular form of an element.
There are several ways to figure out relative ages, that is, if one thing is older than another.
For example if you have a fossil trilobite and it was found in the Wheeler Formation.
In radioactive atoms the nucleus will spontaneously change into another type of nucleus.