SOLUTION: After 3 days a sample of Radon-222 has decayed to 50% of its original amount.
1. What is the half life?
2. How long will it take the sample to decay to 30% of its original amo
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-> SOLUTION: After 3 days a sample of Radon-222 has decayed to 50% of its original amount.
1. What is the half life?
2. How long will it take the sample to decay to 30% of its original amo
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Question 1005725: After 3 days a sample of Radon-222 has decayed to 50% of its original amount.
1. What is the half life?
2. How long will it take the sample to decay to 30% of its original amount?
Please help me !! Answer by fractalier(6550) (Show Source):
You can put this solution on YOUR website! The half-life IS three days, since half of it is gone in that time.
From there we use
A(t) = Ao * (1/2)^(t/3)
.3Ao = Ao * (1/2)^(t/3)
.3 = (1/2)^(t/3)
.3 = 2^(-t/3)
ln .3 = (-t/3) ln 2
ln .3 / ln 2 = -t/3
t = -3ln .3 / ln 2 = 5.21 days
