And carbon dating
Some chemical elements have more than one type of atom. Carbon has two stable, nonradioactive isotopes: carbon-12 (12C), and carbon-13 (13C).In addition, there are trace amounts of the unstable isotope carbon-14 (14C) on Earth.It is not uncommon for a cosmic ray to collide with an atom in the atmosphere, creating a secondary cosmic ray in the form of an energetic neutron, and for these energetic neutrons to collide with nitrogen atoms.When the neutron collides, a nitrogen-14 (seven protons, seven neutrons) atom turns into a carbon-14 atom (six protons, eight neutrons) and a hydrogen atom (one proton, zero neutrons).______________________________________________________________ ____________________________________________________________________ ____________________________________________________________________________________________ _______________________________________________________________ Relative Ages of Rocks: WIki Books (Wiki Books: A project hosted by the Wikimedia Foundation for the creation of free content textbooks) Willard Libby and Radiocarbon Dating.
Following a conference at the University of Cambridge in 1962, a more accurate figure of 5730 years was agreed upon and this figure is now known as the Cambridge half-life.Carbon-14 is radioactive, with a half-life of about 5,700 years.For more information on cosmic rays and half-life, as well as the process of radioactive decay, see How Nuclear Radiation Works. One of the most frequent uses of radiocarbon dating is to estimate the age of organic remains from archaeological sites. Carbon dating, also known as radiocarbon dating, is a method of estimating the age of carbon-bearing materials up to 60,000 years old.