How is 12.011 indicates that carbon is a mixture of isotopes?

Answer 1

The value 12.011 represents the atomic weight of carbon and indicates that it is a weighted average of the masses of its naturally occurring isotopes, primarily carbon-12 and carbon-13, along with trace amounts of carbon-14. Carbon-12 has an Atomic Mass of approximately 12 atomic mass units (amu), while carbon-13 is slightly heavier at about 13 amu. The presence of 12.011 suggests that there are varying proportions of these isotopes in nature, rather than a single, uniform mass for all carbon atoms. This mixture is due to the different numbers of neutrons in the isotopes, leading to their distinct masses.