Radioactive Decay
The half-life of a radioactive substance is 10 days. What fraction of the original amount will remain after 30 days?
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About This Question
- Subject
- physics
- Chapter
- atoms and nuclei
- Topic
- radioactive decay
- Difficulty
- Easy
- Year
- 2025
Solution
Correct Answer:
1/8
- Identify Timing: Life of substance T=30 days. Half-life T1/2=10 days.
- Calculate Number of Half-lives (n):
- n=T1/2T=1030=3 cycles passed.
- Determine Fraction Remaining: The amount remaining is N=N0(21)n.
- Substitution:
- Fraction =(21)3=2×2×21=81.
- Result: 81 of the original quantity remains.
This easy difficulty physics question is from the chapter atoms and nuclei, covering the topic of radioactive decay. It appeared in the 2025 exam.
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