Half-life Time
Prequisite Knowledge
Half-life
Problem
The half-life of a radioactive isotope is 5.7 days. How long will it take to reduce the original amount to 3%?
Solution
N
N
0
=
(
1
2
)
t
t
1/2
0.03 =
(
1
2
)
t
5.7
ln 0.03 =
(
t
5.7
)
ln 0.5
t
= 5.7
(
ln 0.03
ln 0.5
)
= 28.8 days
t
= 28.8 days