Dating old rocks
Over time, carbon-14 decays radioactively and turns into nitrogen.
A living organism takes in both carbon-12 and carbon-14 from the environment in the same relative proportion that they existed naturally.
Some very straightforward principles are used to determine the age of fossils.
Students should be able to understand the principles and have that as a background so that age determinations by paleontologists and geologists don't seem like black magic. Geologists in the late 18th and early 19th century studied rock layers and the fossils in them to determine relative age.
Explore this link for additional information on the topics covered in this lesson: This activity will help students to have a better understanding of the basic principles used to determine the age of rocks and fossils. Objectives of this activity are: 1) To have students determine relative age of a geologically complex area.
2) To familiarize students with the concept of half-life in radioactive decay.
Carbon dating only works for objects that are younger than about 50,000 years, and most rocks of interest are older than that.3) To have students see that individual runs of statistical processes are less predictable than the average of many runs (or that runs with relatively small numbers involved are less dependable than runs with many numbers).