The "alkane series" refers to a group of hydrocarbons that have only single bonds between atoms and have the general formula CnH2n+2. As a result of their simple chemical structure, alkanes are often used as a model for other organic compounds and are commonly found in petroleum and natural gas. Synonyms for the term "alkane series" include "paraffin series" or simply "paraffins." This name comes from the Latin word for "little affinity," reflecting the fact that these molecules are relatively unreactive. Other related terms include saturated hydrocarbons, straight chain hydrocarbons, and n-alkanes, which all refer to particular aspects of the structure and properties of these compounds.