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.Eventually, the salt water will eat through the steel and release the Plutonium (which, as you know, is quite lethal.) They usually talk about either trying to raise the sub or encase it in concrete where it rests. That's why we are called "Carbon-based life forms." Man, I've really watched too much Star Trek.)Scientists use Carbon-14 to make a guess at how old some things are -- things that used to be alive like people, animals, wood and natural cloths. Anyway, they make an estimate of how much Carbon-14 would have been in the thing when it died...
The amount of carbon-14 in the atomosphere is, on an average, relatively constant.
Plants take in carbon-14 through the process of photosynthesis.
It uses the naturally occurring radioisotope carbon-14 (14C) to estimate the age of carbon-bearing materials up to about 58,000 to 62,000 years old.
Carbon has two stable, nonradioactive isotopes: carbon-12 (12C) and carbon-13 (13C).
As long as the organism is alive, the amount of carbon-14 remains relatively constant.