Half-life and Radioactive Decay
Explore the concept of half-life with this Grade 9 science worksheet, covering radioactive decay, calculations, and applications.
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Half-life and Radioactive Decay
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Read each question carefully and provide your best answer. Show all your work for calculations.
1. What is the definition of half-life?
The time it takes for a substance to completely decay.
The time it takes for half of the radioactive nuclei in a sample to decay.
The time it takes for a substance to double its mass.
The time it takes for a substance to become stable.
2. If an isotope has a half-life of 10 years, how much of a 100g sample will remain after 20 years?
50g
25g
12.5g
0g
3. The process by which an unstable atomic nucleus loses energy by emitting radiation is called .
4. After three half-lives, of the original radioactive material remains.
5. All radioactive isotopes have the same half-life.
True
False
6. Carbon-14 dating is used to determine the age of very old rocks.
True
False
7. A radioactive sample initially contains 800 atoms. After 3 hours, 100 atoms remain. What is the half-life of this isotope?
8. Explain one real-world application of half-life.
The graph below shows the decay of a radioactive isotope over time.
9. Based on the graph, what is the half-life of this isotope?