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accountkiller
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Homework Statement
You have two samples that exhibit radioactive decay. The first gives you initially a 1000/s decay rate and after one hour a 500/s decay rate. The second gives you initially a 500/s decay rate and after one hour a 250/s decay rate. Which sample has a higher probability per unit time that any nucelus will decay?
Homework Equations
λ = probability per unit time
N(t) = N0e-λt
Tmean = 1/λ = T1/2/ ln(2)
-dN(t)/dt = λN(t)
The Attempt at a Solution
Does half-life mean the time it takes for the quantity of nuclei to be cut in half, or the time it takes for activity to be cut in half? I thought it was quantity, but the answer to this question is that the probability per unit time is the same for both, so I don't understand why.
-dN(t)/dt = 1000/s
-dN(t)/dt = λN(t) .. but I don't know N(t), so how do I find λ?
Am I just supposed to know that if the activity decreases by half in both, the probability is the same?