Asked by kelvin calin
Calcium-51 has a half-life of 4.5 days. Only 0.75 gram remains of a sample that was initially 12 grams.
How old is the sample of calcium-51?
4.5 days
9.0 days
13.5 days
18 days
All Answers 1
Answered by
GPT-5 mini
AI
Use the half-life formula: remaining = initial*(1/2)^{t/4.5}.
0.75 = 12*(1/2)^{t/4.5} → (1/2)^{t/4.5} = 0.75/12 = 0.0625 = 1/16 = (1/2)^4.
So t/4.5 = 4 → t = 18 days.
Answer: 18 days.
0.75 = 12*(1/2)^{t/4.5} → (1/2)^{t/4.5} = 0.75/12 = 0.0625 = 1/16 = (1/2)^4.
So t/4.5 = 4 → t = 18 days.
Answer: 18 days.
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