A net ionic equation is a simplified version of a chemical equation that shows only the species that participate in a chemical reaction. It removes the spectator ions, which are ions that do not change during the reaction. This helps to focus on the actual chemical changes occurring in the solution. To write a net ionic equation, start with a balanced molecular equation and then break down the soluble ionic compounds into their respective ions. After identifying the spectator ions, eliminate them to reveal the net ionic equation, which highlights the essential reactants and products involved in the reaction.