Isotopes, Half-life (years), Effective Dating Range (years). Dating Sample, Key Fission Product. Lutetium, Hafnium, billion, early Earth. Uranium-.
Radioactive Dating Radioactive clocks Our ancestors measured the passing of time with water clocks or hourglasses. CEA Radioactive hourglasses are used to date the relics of bygone civilizations, by measuring the amount of Carbon, whose decay rate allows for precise age calculations. Carbon is a radioactive carbon isotope present in the atmosphere, plants and living bodies. Radioactive dating can also be applied to the dating of rocks as old as the Earth, of coral and volcanic lava.
Other dating methods using the uranium-thorium isotope used for radioactive dating, for example reveal the amount by which the carbon 14 results need to be corrected. For instance, the correction is an approximate 3, years increase, for ages of the order of 20, years.
A good example is the dating of coral. The moment the coral dies, however, the decay of radioactive elements begins to produce thorium inside the coral.