Fossils are collected along with rocks that occur from the same strata.These samples are carefully cataloged and analyzed with a mass spectrometer.The original atom is referred to as the parent and the following decay products are referred to as the daughter.For example: after the it forms a component of all organic compounds and is therefore fundamental to life. Libby of the University of Chicago predicted the existence of carbon-14 before it was actually detected and formulated a hypothesis that radiocarbon might exist in living matter.The mass spectrometer is able to give information about the type and amount of isotopes found in the rock.
For the first time he was able to exactly measure the age of a uranium mineral.
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.
Shortly after Becquerel's find, Marie Curie, a French chemist, isolated another highly radioactive element, .
The realisation that radioactive materials emit rays indicated a constant change of those materials from one element to another.