The chemical burning central to life’s processing of energy is called a redox reaction. Not the most inviting name, but the archetypal example—a burning log—clarifies the nomenclature. As a log burns, carbon and hydrogen in the wood relinquish electrons to oxygen in the air (remember, oxygen yearns for electrons), bonding them into molecules of water and carbon dioxide, and releasing energy in the process (the very reason fire is hot). When oxygen grabs electrons, we say that it has been reduced (you can think of this as a reduction in oxygen’s yearning for electrons). When carbon or hydrogen
...more
