Question

The half-life of carbon-14 is 5,730 years. Suppose a fossil is found with 30 percent as much of its carbon-14 as compared to a living sample. How old is the fossil?

Answer 1

Explanation:

Find the number of half lives to get to .3 (which is 30%) then multiply by 5730 years per half life:

.3 = (1/2)^n <====solve for 'n'

log .3 / log (1/2) = n = 1.737 half lives

1.737 X 5730 = ~ 9953 years old