Flashcards on Geological Time, Fossils, and Dating Methods
Geological Time, Fossils & Dating Methods: A Student Guide
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Radiometric dating
21 cards
Card 1
Question: What is radioactive decay?
Answer: The spontaneous transformation of an unstable parent isotope into a different daughter isotope (or element) by emitting radiation.
Card 2
Question: In the example where thorium (Th) decays to lead (Pb), which is the parent and which is the daughter?
Answer: Parent element: thorium (Th). Daughter element: lead (Pb).
Card 3
Question: Give one other example of radioactive decay naming the parent and daughter elements.
Answer: Example: Uranium-238 (parent) decays to lead-206 (daughter). (Any other decay process with parent and daughter elements from the content is acceptable
Card 4
Question: For which groups of materials is isotopic (radiometric) dating useful?
Answer: It is useful for materials that contain radioactive parent isotopes and their daughter isotopes, especially igneous rocks.
Card 5
Question: What special property of radioactive decay makes isotopic dating useful for dating rocks?
Answer: Radioactive decay proceeds at a predictable constant rate (characterized by a half-life) independent of external conditions, allowing ages to be calcu
Card 6
Question: Does isotopic dating give absolute age or relative age of a rock?
Answer: Isotopic dating gives the absolute age of a rock.
Card 7
Question: What is the meaning of the term 'half-life' in radioactive decay?
Answer: Half-life is the time required for half of the original parent atoms to decay into daughter atoms.
Card 8
Question: Explain the coin experiment that simulates radioactive decay and what number of coins you'd expect to remove on the first shake starting with 100 head
Answer: Coins start 'heads' (parent); after shaking, roughly 50% flip to 'tails' (decayed). You would expect to remove about 50 coins on the first removal.
Card 9
Question: Why can't you predict when the last coin will flip in the coin experiment?
Answer: Because the process is random; while the average behavior (50% per interval) is predictable, the exact time for the last individual to flip is unpredi
Card 10
Question: How is the coin experiment analogous to radioactive decay?
Answer: Both are random processes where each individual has a constant probability of 'decaying' per interval, producing an overall exponential decline with p