A 32g phosphorus is decayed and 2g remains undecayed after 60 days. The half-life of phosphorous is:
Correct answer: D. 15 days
- A. 5 days
- B. 6 days
- C. 10 days
- D. 15 days
Explanation
1 half life = 16g 2 half life = 8g 3 half life = 4g 4 half life = 2g 60/4=15 days
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About Half-life and Rate of Decay
Half-life is the time required for half the unstable nuclei in a sample to decay, and it remains constant for a particular radioactive nuclide. Questions use the exponential decay law, decay constant, activity, remaining quantity and mean life. Radioactive decay is random for individual nuclei but predictable for large samples.
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