ANTH 1210 Chapter Notes - Chapter 4: Willard Libby, Heinrich Schliemann, Radionuclide
Document Summary
Coin with date, foundation deposits, corner stones, monumental inscriptions (roman emperors give date of year of reign), time capsules. Texts (troy and the iliad) heinrich schliemann . Radioactive isotope unstable, decay at constant rate. Measure amount if decay, calculate amount of time since decay began. Cosmic rays hit nitrogen atoms, cause them to release a proton becoming carbon 14 (isotope of carbon. Through oxidation, c14 bonds with 2 oxygen atoms forming carbon dioxide. The time that half of the radioactive material will decay (change) into a nonradioactive form. Since the half life of c14 is know the amount of time elapsed since the death of the organism can be measured. Half life decay rate back to n14. Start w 15cpm/gm: sample 5730 years okd. 1. 625 cpm/gm (counts per minute) measuring amount of radioactivity in object. Radio-carbon dating limits : traditional 40000 years ago.