A variety of organic chemistry reactions can be classified broadly as reactions that require the use of a base or contain the nucleophile. Bases react to deprotonate acids. This means that when a base is present, the proton with the highest acidity is eliminated out of organic compounds with the exception of any steric effects that could cause an acidic proton to react to the base. Nucleophiles are compounds that is able to react with an electrophilic atom which is bound to a group leaving. Electrophiles have an C atom that is attached to an atom much more negative than C. This provides the C atom the advantage of having a positive charge, which is able to receive electrons from the nucleophile. When determining the outcome of a chemical reaction, it is essential to identify whether the reaction will function as a nucleophile, or base.