Log in Sign up. How can we help? What is your email? Upgrade to remove ads. Original dating of Earth was done by fossils. Radiometric geochronology; uses decay of unstable or radiogenic isotopes to measure the age of a mineral. Same mineral, different number of neutrons in the nucleus. Amount of time needed for half the amount of a parent isotope to decay to a daughter isotope.
Loss of a He ion Lose 2P and difference relative and absolute dating. Loss of electron "Turns" a neutron into a proton. Addition of a beta particle "electron" "Turns" a proton into a neutron.