Atoms become ions by gaining or losing electrons, giving them a positive or negative charge. Ions that have lost electrons, and therefore take on a positive charge, are cations. Whereas ones that gain electrons to become negative are anions. The most basic ions, called monatomic ions, are formed from single atoms.
05:20. Arabic numerals are already being used to denote how many atoms of an element there are in a molecule, 05:26. the molecule’s charge, its oxidation state, the number of molecules reacting in an equation.