Post-UTME Physics 2019 Objective — Question 9
Question 9 of 20 from the Post-UTME Screening (Post-UTME) Physics 2019 Objective paper, with the correct answer and a full explanation.
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A radioactive gas has a half-life of 4 days. What fraction of the gas remains after 12 days if the original mass was 2g?
- A. 1/8Correct
- B. 1/4
- C. 1/2
- D. 3/2
Explanation
12 days = 3 half-lives. Fraction remaining = (1/2)^3 = 1/8.
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