Oxidation-Reduction Reactions, more commonly called Redox Reactions, are reactions involving the transfer of electrons between atoms. In a redox reaction, one atom gains electrons while another atom loses electrons. Often this process involves elemental atoms, that is, atoms without an electric charge, but this process always involves ions, atoms or molecules that have an electric charge. Redox reactions are different from acid-base reactions in that acid-base reactions involve the movement of atoms, molecules, or ions to form new chemical bonds but the electrons do not move from one particle to another. Oxidation is the term for the loss of electrons, while reduction is the term for the gain of electrons. Whenever oxidation happens, reduction must be happening as well. For this reason, whenever we talk about oxidationo or reduction by themselves, we call them "half-reactions" because they only represent half of the entire reaction.