A radioactive isotope has a half-life of 5,000 years. A rock originally contained 16 grams of radioactive isotope, and now contains 4 grams. Approximately how many years old is the rock?

a) 75,000 years
b) 5 million years
c) 3,750 years
d) 10,000 years
e) 15,000 years


Ans: d) 10,000 years

Biology & Microbiology

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