So what is electrochemistry? Many chemical reactions include the transfer of electrons from one molecule or atom to another. The loss of electrons is called oxidation, and the accepting of electrons is called reduction. In nature, these reactions appear as couples because one is donating the electron and the other is accepting it. This is what is meant when people talk about redox reactions. These kinds of reactions are all around, in iron rusting, materials burning, copper turning green, apples turning brown, bleaching hair, or digesting food, which happens inside everyone. Initiating reductions takes some energy, so classic examples are the cleaning of silverware by cooking it with saltwater and aluminum foil or photosynthesis. What if this transfer of electrons could be controlled or even exploited?