Carbon-14 is most abundant in atmospheric carbon dioxide because it is constantly being produced by collisions between nitrogen atoms and cosmic rays at the upper limits of the atmosphere.

The rate at which C atoms, half of them will decay in 5730 years.

The 6 proton 6 neutron atoms are said to have a mass of 12 and are referred to as "carbon-12." The nuclei of the remaining one percent of carbon atoms contain not six but either seven or eight neutrons in addition to the standard six protons.

Levels of C can represent either mixtures of modern and dead carbon or carbon that was fixed from the atmosphere less than 50,000 years ago.

Signals of this kind are often used by chemists studying natural environments.

Later called Ötzi the Iceman, small samples from his body were carbon dated by scientists.

The results showed that Ötzi died over 5000 years ago, sometime between 33 BC. It is found in the air in carbon dioxide molecules.

The amount of carbon-14 in the air has stayed the same for thousands of years.

There is a small amount of radioactive carbon-14 in all living organisms because it enters the food chain.

All carbon atoms have a nucleus containing six protons.

Ninety-nine percent of these also contain six neutrons.

For example all comparisons are done in UTC or in the timezone of the datetime being used.