Eli5: what are things like carbon-12? Are they carbons but with a nucleon mass of 12? And how are electrons related?

Question

Eli5: what are things like carbon-12? Are they carbons but with a nucleon mass of 12? And how are electrons related?

In: Chemistry

Answer 1

Carbon is any atom with 6 protons. Carbon-12 is specifically atoms with 6 protons and 6 neutrons (for a total of 12 nucleons). It is the most common form of carbon naturally occurring (98.89% of natural carbon is carbon-12).

Electrons don’t factor into whether carbon is carbon-12. Electrons only care about the number of protons, not the number of neutrons. All carbon has 6 protons, so all carbon is carbon to an electron.