Ionic compounds contain charged particles called ions. For electrolysis to work, the ions must be free to move. Ions are free to move when an ionic substance is dissolved in water or when melted. Positively charged ions move to the negative electrode during electrolysis and they receive electrons. Negatively charged ions move to the positive electrode during electrolysis and lose electrons.Both the products of the dissociation are collected at the electrodes. This is called electrolysis.