A sample of wood contains 12.5% of carbon-14. What is the estimated age of this sample?

How old is an artifact that contains 12.5 percent of its original carbon-14?

:

The generally accepted value for the half-life of Carbon-14 is 5730 yr

:

Let t = time for 12.5% of the artifact to remain

Let the initial amt = 1

:

1*2^ (-t/5730) =.125

use nat logs

ln (2) = ln (.125)

=

= - 3

t = - 3 * - 5730

t = 17,190 yrs