ConcepTest: Oldest Rock Dating #2
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.
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