Redox reactions

Redox reactions (reduction-oxidation reactions) are (probably) the most normal reactions in the universe, and are reactions where two species react with eachother, causing one electron transfers from one species to the next. This means one species in the reaction loses an electron (is reduced), while the other gains an electron (is oxidized). The idea that something gains an electron and is still "reduced", might seem counterintuitive, but the reasoning is that the electron gives atoms a negative charge, reducing the electric charge.

 Unlike reduction and oxidation reactions, redox reactions are not so easy to identify (not on our level anyway). For an example, (Cu2O > Cu + CuO) is a redox reaction. The clue here is that oxygen is involved, and that something happened with the species containing the oxygen. Another example is (Cl2 + 2*F > F2 + 2*Cl-). The clue here is that one species lost its negative charge to another one. Some are even trickier, but we won't have to do those until next year. Don't get it? That's okay. We can eat ice cream in the tub together.