SOLUTION: in 10 years, 25% of a radioactive substance decays. What is its half-life?
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Question 763706: in 10 years, 25% of a radioactive substance decays. What is its half-life?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
in 10 years, 25% of a radioactive substance decays.
What is its half-life?
:
That means 75% remains
:
The radio active decay formula
A = Ao*2^(-t/h), where
A = amt remaining after t
Ao = initial amt (t=0)
t = time of decay
h = half life of substance
:
Let initial amt = 1 then resulting amt = .75
1*2^(-10/h) = .75
ln(2^(-10/h)) = ln(.75)
*ln(2) = ln(.75)
=
= -.415
-.415h = -10
h =
h = +24 yrs is the half life
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