We've talked about ions before. Now it's time to get down to basics. The atomic number of an element, also called a proton number, tells you the number of protons or positive particles in an atom. A normal atom has a neutral charge with equal numbers of positive and negative particles. That means an atom with a neutral charge is one where the number of electrons is equal to the atomic number. Ions are atoms with extra electrons or missing electrons. When you are missing an electron or two, you have a positive charge. When you have an extra electron or two, you have a negative charge.