Quote by SReinhardt
Wouldn't there have to be a negative sign in there somewhere >_>
I believe you have to use integrals to solve that, which I haven't done yet.

yeah it should have a minus sign, good! :)
Solving this:
[tex] \int N ^{1}dN =  \int \lambda dt [/tex]
[tex] \ln(N(t))  \ln(N(0)) = \lambda t [/tex]
[tex] \ln(N(t)/N(0)) = \lambda t [/tex]
[tex] N(t)/N(0) = e^{\lambda t } [/tex]
[tex] N(t) = N(0) e^{\lambda t } [/tex]
Lambda is the number of decays per unit time, is related to half life by:
[tex] \lambda = \frac{\ln 2}{T_{1/2}} [/tex]