In ions, the numbers of electrons and protons are not equal.Similarly, the negative charge on anion equals the number of electrons it has gained so, S2- has 18 electrons rath than 16,Regardless of how many electrons are present, every sulfur nucleus contains 16 protons. The identity of an element is determined by the number of protons, not the number of electrons. When the element is neutral, the number of positively charged protons and negatively charged electrons will be equal. When there are more electrons than protons, the ion will be negative, as in this example. When there are more protons than electrons, the ion will be positive.