Carbon exists in three isotopes, $^{12}\text{C}$, $^{13}\text{C}$ and $^{14}\text{C}$. Why do these three isotopes all show the same chemical properties?
- AThey all have the same atomic mass.
- BThey all have the same number of electrons in their outer shell.
- CThey all have the same number of electron shells.
- DThey all have the same number of nucleons.