<P> The least complex aliphatic compound is methane (CH). </P> <P> Most aliphatic compounds are flammable, allowing the use of hydrocarbons as fuel, such as methane in Bunsen burners and as liquefied natural gas (LNG), and acetylene in welding . </P> <P> The most important aliphatic compounds are: </P> <Ul> <Li> n -, iso - and cyclo - alkanes (saturated hydrocarbons) </Li> <Li> n -, iso - and cyclo - alkenes and - alkynes (unsaturated hydrocarbons). </Li> </Ul>

What is meant by aliphatic and aromatic compounds