Passing an electric current through an ionic compound will split it into its component elements.This is called electrolysis and was the process used to isolate many new elements for the first time.When the power source is turned on,the positive and negativeions in the compound are attracted to their oppositely charged electrodes.At the cathode,positive ions receive electrons and,at the anode,negative ions lose electrons,so the ions become neutral atoms again.The pure elements build up at each electrode and can be collected.Water is an ionic compound that can be split into hydrogen and oxygen in this way.