Question

The doctor measured the count rate from the sample. the count rate was 80 seconds per second.

half life of radium-226 = 1600years

calculate the count rate in 6400 years

Answer 1

$A(t)=A_0\cdot2^{-t/T_{1/2}}\to$

$A=80\cdot2^{-6400/1600}=5\ (Bq)$ . Answer