A piece of wood from an archeological site has a carbon-14/carbon-12 ratio that is
12.5% that of the carbon-14/carbon-12 ratio in living materials. How old is the wood
from the temple site? The half –life of C-14 is 5,730 years.
Carbon-14/carbon-12 ratio at the moment when organism die is the same as every other living thing. Carbon-14 decays and is not replaced. Carbon-14 decays with its half-life of 5,730 years. At the same time the amount of carbon-12 remains constant in the sample. By looking at the carbon-14/carbon-12 in the sample and comparing it to the ratio in a living organism, it is possible to determine the age of a remain. To calculate how old a sample is by carbon-14 dating, we must use a formula: t = [ ln (Nf/No) / (-0.693) ] x t1/2 where: Nf/No is the percent of carbon-14 in the sample compared to the amount in living tissue; t1/2 is the half-life of carbon-14. t = [ ln 0.125 / (-0.693) ] x 5,730=17,104 years