The characteristic of the compound you are referring is essential to where on the functional groups it belong. Furthermore, the basic functional groups among the hydrocarbons are: alkane, alkene, alkyne, benzene, and others that basically has a hydrogen atom and a carbon atom.
A chemical change affects on the molecular level of matter, which makes it irreversible. Combustion is a pretty good exmple. Physical changes are reversible and dont alter the formula. Hope this helped!
