LEO goes GER

To help yourself remember which is oxidation and which is reduction in terms of electrons, memorize the phrase LEO goes GER (Lose Electrons Oxidation Gain Electrons deduction). 

Before we discuss the reduction potentials of the alkali metals, we should recall some definitions related to oxidation—reduction, or redox, reactions. (This is but a sparse review. You may need to consult your introductory textbook or lecture notes for further clarification.) Recall that when a substance is reduced, its oxidation state (or the oxidation state of some constituent element) is decreased. When a substance is oxidized, the oxidation state increases. Reduction is associated with a gain of electrons, whereas oxidation corresponds to a loss. (Some students keep these definitions straight by using the mnemonic, or memory device, LEO goes GER, which stands for Loses Llectrons Oxidized, Gains Electrons Reduced.)... 

Two commonly used redox / V I reaction memorization aids are 1) LEO the lion goes GER (Lose Electrons Oxidation, Gain Electrons Reduction) and OIL RIG (Oxidation Involves Loss of electrons, Reduction Involves Gain of electrons). 

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