The existence of so many organic compounds is due primarily to the ability of carbon atoms to combine with other carbon atoms, forming chains of different lengths and rings of different sizes. The elements, other than carbon, most frequently found in organic compounds are hydrogen, oxygen, nitrogen, sulfur, the halogens, phosphorus, and some of the metals. Although the number of organic compounds is vast, the study of organic chemistry is greatly simplified by the fact that the chemistry of carbon compounds can be organized around"functional groups", each of which imparts similarities in chemical properties.The existence of so many organic compounds is due primarily to the ability of carbon atoms to combine with other carbon atoms, forming chains of different lengths and rings of different sizes. The elements, other than carbon, most frequently found in organic compounds are hydrogen, oxygen, nitrogen, sulfur, the halogens, phosphorus, and some of the metals. Although the number of organic compounds is vast, the study of organic chemistry is greatly simplified by the fact that the chemistry of carbon compounds can be organized around “functional groups”, each of which imparts similarities in chemical properties