# What is radiometric dating of fossils

The half-life is the amount of time it takes for one half of the initial amount of the parent, radioactive isotope, to decay to the daughter isotope.Thus, if we start out with 1 gram of the parent isotope, after the passage of 1 half-life there will be 0.5 gram of the parent isotope left.Despite this, the momentum gained in the two decades prior to 1972 has made 4.5 b.y.a popularly accepted “universal constant” even though the foundations on which it was based have been virtually removed.We can see how do deal with this if we take a particular case. For example the amount of Rb in mantle rocks is generally low, i.e. The mantle thus has a low If these two independent dates are the same, we say they are concordant.Despite seeming like a relatively stable place, the Earth's surface has changed dramatically over the past 4.6 billion years.

The basic theory of radiometric dating is briefly reviewed.

It wasn't until well into the 20th century that enough information had accumulated about the rate of radioactive decay that the age of rocks and fossils in number of years could be determined through radiometric age dating.

This activity on determining age of rocks and fossils is intended for 8th or 9th grade students.

2) To familiarize students with the concept of half-life in radioactive decay.

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).