Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

10. Suppose th at you collect a crystal, and you bust it open in the lab and you

ID: 3166472 • Letter: 1

Question

10. Suppose th at you collect a crystal, and you bust it open in the lab and you determine that it has a ratio of radioactive elements X and Y (where X decays into Y with a half life rate of 1500 r) Your calculations tell you that 1/8 of the original amount of X (when the crystal was forme remains. How old is the crystal? d) a. 600,000 years old b. 37,500 years old c. 450,000 years old d. 1,200,000 years old 11. Furth er suppose that you describe this measurement and conclusion to a relative that does not accept your claim that anything on Earth could be older than 10,000 years old. a. Argue why radiometric dating can be trusted? (2 pts)

Explanation / Answer

10. Answer: Option C is correct.
Explanation:
First half-life = 15000 yrs
After the first half-life, 1/2 of the original X would be left.

Second half-life = 15000 + 15000 yrs
After the second half-life, 1/4 of the original X would be left.

Third half-life = 15000 + 15000 + 15000 yrs
After the thirds half-life, 1/8 of the original X would be left.

Total number of half-lives = 3
Time = 450000 yrs

11. Radiometric dating is a highly reliable technique to calculate the age of rocks/fossils. Since it is a phenomenon that depends on the decomposition of a radioactive nucleus, it is a highly sensitive method. Each radioactive nucleus has a specific half-life. So, we can calculate the age of a rock/fossil by measuring the final ratio of the daughter nucleus to the parent nucleus. The precision of a dating method depends upon the half-life of the radioactive nuclide used.

Hire Me For All Your Tutoring Needs
Integrity-first tutoring: clear explanations, guidance, and feedback.
Chat Now And Get Quote