Electrolysis is the process by which ionic substances are decomposed (broken down) into simpler substances when an electric current is passed through them.
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 molten (melted). For example, if electricity is passed through copper chloride solution, the copper chloride is broken down to form copper metal and chlorine gas.
- Positively charged ions move to the negative electrode during electrolysis. They receive electrons and are reduced.
- Negatively charged ions move to the positive electrode during electrolysis. They lose electrons and are OXIDISED