This is a stable condition, and there are no more changes in the atomic nucleus.
That chance of decay is very small, but it is always present and it never changes.
In other words, the nuclei do not "wear out" or get "tired".
The teacher should tell the students that there are two basic principles used by geologists to determine the sequence of ages of rocks.
They are: Principle of superposition: Younger sedimentary rocks are deposited on top of older sedimentary rocks.
It is estimated to require four hours of class time, including approximately one hour total of occasional instruction and explanation from the teacher and two hours of group (team) and individual activities by the students, plus one hour of discussion among students within the working groups.
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.
Return to top Each team of 3 to 5 students should discuss together how to determine the relative age of each of the rock units in the block diagram (Figure 1).
After students have decided how to establish the relative age of each rock unit, they should list them under the block, from most recent at the top of the list to oldest at the bottom.
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.
Students not only want to know how old a fossil is, but they want to know how that age was determined.