An organic compound is a compound containing carbon in combination with one or more elements. Organic compounds are generally characterized by chains of connected carbon atoms. Hydrocarbons contain only carbon and hydrogen, while many other organic compounds contain carbon, hydrogen, and oxygen. Other major elements in naturally occurring organic compounds are nitrogen, phosphorus, and sulfur. Exceptions to the classification of carbon-containing compounds as organic compounds include carbon dioxide, carbon monoxide, carbon disulfide, carbon tetrachloride, hydrogen cyanide, carbonates, and carbides, which have traditionally been regarded as inorganic compounds.

It was commonly believed that compounds of carbon could only be produced by the vital forcefound in living organisms. However, in 1828, Wöhler found, by accident, that the application of heat to ammonium cyanate, an inorganic compound, caused it to change to urea, a compound thought to be formed only by living organisms. Today many organic compounds...