7}^{14}\textrm{N}\) and \(_{6}^{14}\textrm{C}\) are not isotopes. They have the same mass number, A, but different atomic number, Z, and different chemical symbol - they are not the same element.

We are shown that the atomic number is the number of protons in an atom. We see that the mass number minus the atomic number is the number of neutrons. We complete the atomic structure by ...