The half-life of Radium is about 1600 years. If a rock initially contains 1 g of Radium, the amount left after 6400 years will be about:
Correct answer: C. 62 mg
- A. 938 mg
- B. 31 mg
- C. 62 mg
- D. 16 mg
Explanation
Amount remaining after n half-lives = 1/2n(mo)Number of half-lives, n = t/ T1/2 = 6400/1600= 4Amount remaining after 4 half-lives = 1/24(1)= 0.0625g = 62 mg
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