For example, the atomic number of sodium is 11. Every sodium atom has 11 protons and 11 electrons. It has 11 positive charges and 11 negative charges. The mass number of an atom is its total ...

^{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. If the number of protons ...