Explain the process of carbon 14 radioactive dating
The carbon-14 isotope would vanish from Earth's atmosphere in less than a million years were it not for the constant influx of cosmic rays interacting with molecules of nitrogen (N) into organic compounds during photosynthesis, the resulting fraction of the isotope 14C in the plant tissue will match the fraction of the isotope in the atmosphere.
After plants die or are consumed by other organisms, the incorporation of all carbon isotopes, including 14C, stops.
Carbon-14 is radioactive, with a half-life of about 5,700 years.
For more information on cosmic rays and half-life, as well as the process of radioactive decay, see How Nuclear Radiation Works.
The ratio of normal carbon (carbon-12) to carbon-14 in the air and in all living things at any given time is nearly constant.
Maybe one in a trillion carbon atoms are carbon-14.
Raw (i.e., uncalibrated) radiocarbon ages are usually reported in radiocarbon years "Before Present" (BP), with "present" defined as CE 1950.Because the cosmic ray bombardment is fairly constant, there’s a near-constant level of carbon-14 to carbon-12 ratio in Earth’s atmosphere.Organisms at the base of the food chain that photosynthesize – for example, plants and algae – use the carbon in Earth’s atmosphere.There are also trace amounts of the unstable radioisotope carbon-14 (14C) on Earth.Carbon-14 has a relatively short half-life of 5,730 years, meaning that the fraction of carbon-14 in a sample is halved over the course of 5,730 years due to radioactive decay to nitrogen-14.