Pulling Compounds Apart With Electricity

Five parts paying a debt three earlier tracks ran up. Electrolysis is leaned on whenever a metal is too reactive to be freed by carbon, and it was never explained. It starts with a fact that needs no apparatus: solid salt conducts nothing and molten salt conducts well, with nothing added. The ions were always there — melting is simply what lets them move, which is why an electrolyte has to be a liquid. The second part follows them to the electrodes, where positive ions gain electrons and negative ions lose them, and takes the chance to define oxidation and reduction properly by electrons rather than by oxygen. The third is where the topic gets hard: dissolve something in water and the water supplies two more ions, so each electrode becomes a competition — which is why electrolysing salt solution gives hydrogen rather than sodium. The fourth opens the aluminium cell the metals track said was needed, where the step that made the metal cheap was not electrical at all but finding a solvent. And the last asks what the technique is for, which turns out to be two different things: splitting compounds nothing else can split, and moving metal through a liquid without splitting anything at all.