Spectator ions are ions that is in the reaction but does not actively take part in it. It could be determined by presenting compounds in its ionic form. Then, if the ions appears both in the reactant and the product side, then it is a spectator ion. In this example, that would be NH4+ or the ammonium ion.
-A spectator ion is an ion that exists in the same form on both the reactant and product sides of a chemical reaction. The ion is unchanged on both sides of a chemical equation and does not affect equilibrium. The spectator ions are ignored when writing ionic equations.
Like charges repel each other; unlike charges attract. Thus, two negative charges repel one another, while a positive charge attracts a negative charge.
