Question

A prehistoric bone is found at an excavation site. If the bone originally contained 22 kg of carbon−14, how much would remain after 11,400 years?

Answer 1

assuming 5730 year half life

a = Ai e^-kt
a/Ai = .5 = e^-k(5730)
ln .5 = -k(5730)
k = 1.21 *10^-4

so
a = 22 e^-(1.21*10^-4*11400)
= 22 * e^-1.38
= 22* .252
= 5.54 kg