If we know how much C-14 was in the living tissue, we can measure the amount of C-14 in the dead plant or animal and then compare these to assess how long it has been dead. We can do this because we know the decay rate of C-14 (it has a half-life of 5,730 years). The result is the radiocarbon age of the sample.
Why is carbon-14 good dating?
Over time, carbon-14 decays in predictable ways. And with the help of radiocarbon dating, researchers can use that decay as a kind of clock that allows them to peer into the past and determine absolute dates for everything from wood to food, pollen, poop, and even dead animals and humans.
What is carbon 14 dating and why is it useful?
Radiocarbon dating is a method that provides objective age estimates for carbon-based materials that originated from living organisms. An age could be estimated by measuring the amount of carbon-14 present in the sample and comparing this against an internationally used reference standard.