And why so? Well, each carbon nucleus MUST contain 6 positively-charged positively charged nuclear particles, i.e. 6 nuclear protons...for carbon #Z=6#...and this property defines the identity of the atom.
But for #""^12C#, the nucleus contains 6 neutrally-charged nuclear particles, i.e. 6 neutrons. And for #""^14C#, the nucleus contains 8 neutrally-charged nuclear particles, i.e. 8 neutrons. This aspect of atomic structure is (I think) pretty straight-forward and accessible. And a little bit of time and study would pay good dividends. The massive nuclear particles engage in the strong nuclear force, an attractive force that operates at incredibly tiny nuclear ranges...
Note that the #""^13C# isotope is very commonly used as a spectroscopic tool in organic chemistry. How many protons and how many neutrons in the nuclei of this isotope?
