Question 1129962
The​ half-life of a radioactive substance is 50 years.
 If you start with some amount of this​ substance, what fraction will remain in 100 ​years? What fraction will remain in 300 ​years? 
:
The radio active decay formula: A = Ao*2^(-t/h), where
A = remaining amt after t time
Ao = initial amt
t = time of decay
h = half-life of substance
:
let initial amt = 1
t = 100 yrs
A = 1*2^(-100/50)
A = .25
The fraction that will remain in in 100 years is the following: .25 or {{{1/4}}}
:
t = 300
A = 1*2^(-300/50)
A = .015625  
The fraction that will remain in in 300 years is the following: .015625 or {{{1/64}}}