Radioactive dating and carbon 14 and nitrogen 14
Plants take in carbon dioxide, incorporating in their tissues both carbon-14 (unstable) and normal carbon-12 (stable) in the same proportion as they occur in the atmosphere .
Carbon-14 then moves up the various food chains to enter animal tissueagain, in about the same ratio carbon-14 has with carbon-12 in the atmosphere.
Half of it will decay in about 5,730 years to form nitrogen.
Half of the remainder will decay in another 5,730 years, and so on.
The helium still locked in the samples was studied as well as the rate at which the helium diffused from the rock.
As our knowledge continues to grow, what we know continues to be in agreement with Scripture.
Radiocarbon ages less than 3,500 years old are probably accurate.
Afterward, less carbon would be available to enter the atmosphere from decaying vegetation.
With less carbon-12 to dilute the carbon-14 continually forming from nitrogen in the upper atmosphere, the ratio of carbon-14 to carbon-12 in the atmosphere would increase.