# Radiometric dating wikipedia the encyclopedia

The mathematical expression that relates radioactive decay to geologic time is: This equation uses information on the parent and daughter isotopes at the time the material solidified. It shows the age of the sample, and the original composition.

The method works best if neither the parent nuclide nor the daughter product enters or leaves the material after its formation.

A mass spectrometer is an instrument that separates atoms based on their mass.

Because geochronologists want to measure isotopes with different masses, a mass spectrometer works really well for **dating** things.

*Radiometric* *dating* depends on the chemistry and ratios of different elements. Take, for example, zircon, which is a mineral; its chemical formula is Zi Si O 4 , so there is one zirconium Zi for one silicon Si for four oxygen O.

Most estimates of the age of the earth come from **dating** meteorites that have fallen to Earth because we think that they formed in our solar nebula very close to the time that the earth formed.**Radiometric** **dating** is the use of radioactive and radiogenic those formed from the decay of radioactive parents isotopes isotopes are atoms of the same element that have different numbers of neutrons in their nuclei to determine the age of something.It is commonly used in earth science to determine the age of rock formations or features or to figure out how fast geologic processes take place for example, how fast marine terraces on Santa Cruz island are being uplifted.*Radiometric* *dating* relies on the principle of radioactive decay.All radioactive isotopes have a characteristic half-life the amount of time that it takes for one half of the original number of atoms of that isotope to decay.