Dating rocks using radioactive decay


dating rocks using radioactive decay-84

When a living thing dies, its radiocarbon loss (decay) is no longer balanced by intake, so its radiocarbon steadily decreases with a half-life of 5,730 years.

If we knew the amount of carbon-14 in an organism when it died, we could attempt to date the time of death.

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.

However, before accepting any radiocarbon date, one should know how the technique works, its limitations, and its assumptions.