“What happens when ions of opposite and equal charge react?”
Let’s think about something. We know that ions are atoms with a net electric charge. We also know that when a positive and a negative charge are close to each other, there will be an electric force that pulls them together. So what happens when ions with charges of equal magnitude and opposite sign come within the vicinity each other? Well, if we use our own scientific intuition, then we would know that there will be an attractive force between the objects, causing them to be pulled together. These atoms will form a bond which chemists have decided to term an ionic bond. Ionic bonds are between metals and non-metals, are very hard to break (often melting only at high temperatures), and can be conductive when they are in liquid form.