You can put this solution on YOUR website! Strontium-90 has a half-life of 28 years.
If a 2.10 mg sample was stored for 180 years, what mass of Sr-90 would remain?
:
The radioactive decay formula:
A = Ao*2^(-t/h)
where
A = resulting amt after t yrs
Ao = initial amt
t = time in yrs
h = half-life of substance
:
A = 2.1*2^(-180/28)
you can do this just as it is on a good calc
A = .02438 mg remain after 180 yrs
