The half-life of a radioactive element is 130 days, but your sample will not be useful to you after 80% of the radioactive nu
clei originally present have disintegrated. About how many days can you use the sample? Round to the nearest day.
1 answer:
Answer:
We can use the sample about 42 days.
Step-by-step explanation:
Decay Equation:



Integrating both sides


When t=0, N=
= initial amount




.......(1)
.........(2)
Logarithm:
130 days is the half-life of the given radioactive element.
For half life,
,
days.
we plug all values in equation (1)






We need to find the time when the sample remains 80% of its original.







We can use the sample about 42 days.
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Step-by-step explanation:
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