Electrolysis is used in the mining industry to split reactive metals from their ores after they are taken from the ground. It is also used to plate (cover) things with metal because it costs less than using, for example, 100% pure solid gold to make jewellery.
Electrolysis makes the anions (negative ions) go to the anode (positive electrode) and the cations (positive ions) go to the cathode (negative electrode). So, for example, oxygen would go to the anode and iron would go to the cathode.
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