What is electrolysis?

• A. The decomposition of a compound by passing an electric current through it.
• B. The formation of a compound by reaction with electric current.
• C. The charging of ions in solution.
• D. The separation of a mixture by magnetic fields.

Answer: (A)

Electrolysis is the decomposition of a compound by passing an electric current through it. When an electrolyte is made to conduct electricity, ions move to the electrodes: cations go to the cathode and gain electrons (reduction), while anions go to the anode and lose electrons (oxidation). The electrical energy forces these redox reactions, breaking the compound into simpler substances—like melting a salt and producing metal and a gas. This is different from forming new substances with electricity, charging ions as a simple action, or separating mixtures with magnetic fields, which do not involve breaking a compound apart with an electric current.