Organic compounds are those that contain carbon, and organic chemistry is the study of those compounds. Inorganic chemistry is the study of the elements and all non-carbon compounds. Carbon compounds are of tremendous everyday importance to life on earth and are the basis of all life processes. An additional reason for the existence of so many organic compounds is the phenomenon of isomerism.
Isomers are compounds which have the same molecular formula but different arrangements of atoms.
All organic compounds are grouped into classes based upon characteristic features called functional groups identified by their atoms and types of bonds. Functional groups determine chemicxal and phsical properties. Compounds with their functional groups are represented by two types of structural formulas. Expanded structural formulas show all the covalent bonds, while condensed structural formulas show no covalent bonds or only selected bonds. The bond angles are 109.5 degrees.