ConcepTest: Oldest Rock Dating #2
This material was originally created for
Starting Point:Introductory Geology and is replicated here as part of the SERC Pedagogic Service.
Initial Publication Date: May 8, 2006
Question:
The world's oldest known rock is approximately 4 billion (4,000 million) years old. What are the approximate relative percentages of parent (Uranium-235) and daughter (Lead-207) isotopes? The half-life of 235U = 704 million years.
a. 35% parent & 65% daughter
b. 12% parent & 88% daughter
c. 2% parent & 98% daughter
d. 0.5% parent & 99.5% daughter
a. 35% parent & 65% daughter
b. 12% parent & 88% daughter
c. 2% parent & 98% daughter
d. 0.5% parent & 99.5% daughter
Student Responses:
No data yet. The correct response is c.
If you would like to help acquire more Before and After statistics for this example, please contact the authors (see link at top of page).
References and Notes:
The use of ConcepTests and Peer Instruction is discussed in detail on the ConcepTest page.
McConnell, D.A., Steer, D.N. and Owens, K.A., 2003, Assessment and Active Learning Strategies for Introductory Geology Courses, Journal of Geoscience Education, 51(2), 205-216.
McConnell, D.A., Steer et al., 2006, Using Conceptests to Assess and Improve Student Conceptual Understanding in Introductory Courses, Journal of Geoscience Education, (54(1), 61-68.