EARTH 7 Lecture Notes - Lecture 4: Great Oxygenation Event, Radiocarbon Dating, Exponential Decay
Document Summary
At time zero, the radioactive mineral is all parent atoms, and eventually daughter atoms will gradually build up over time. Carbon 14 dating cannot be used for dinosaurs since it decays so fast (half life of about. Example problem: the half-life of potassium-40 is 1. 3 billion years. Given that three half lives pass (3. 9 billion/1. 3 billion=3), it is * * =12. 5% Fossil snail has 100 atoms c-14 and 1500 atoms n-14. How long ago did the snail live (when did it die?) 20000 years ago, since there are 1600 total atoms, and after 4 half lives the total becomes 100. Through dating rocks, we discovered the earth to be around 4. 4-4. 5 billion years old, and the moon to be 4. 5 billion years old. Meteorites thought to contain unaltered material from when the solar system was formed, about. For the purposes of this class, the earth is 4. 5 billion years old.
