Question

Archaeologists found an old campfire site. Carbonated firewood was found in the excavation, the ratio of carbon-14 and carbon-12 isotopes of which had decreased from the corresponding sample of fresh firewood to 13.2%. How old was the campfire site?

Answer 1

$N(t)=N_0e^{-\ln2\cdot t/T_{1/2}}$

For carbon-14 $T_{1/2}=5730 \ \ years$

$0.132N_0=N_0e^{-\ln2\cdot t/T_{1/2}}\to 0.132=e^{-0.69t/(5730\cdot365\cdot24\cdot3600)}\to$

$t=16739\ \ years$ . Answer