A functional group is an aspect of organic chemicals or compounds that are expected to react or interact with other elements, thanks to its knowledge of how other elements that comprise identical types of molecular parts have proven to react. A functional group could be a group of atoms that are usually part of a molecule. They are attached to each other courtesy a covalent bond, lending specific chemical and physical properties to the molecule, besides playing a predictable role in chemical reactions. And these atoms could be of different or identical elements.

Organic chemistry has several functional groups. Hydroxyl, alkene, alkyne, ketone, aldehyde, carboxylic acid, amine, amide, ester, ether, etc. are functional groups. Identifying these groups and learning how they react is integral to organic chemistry. Elements have distinctive traits, which stay the same at all times. However, a functional group’s properties may change with location or across molecules and their proximity to other functional groups in the same molecule, since most molecules comprise multiple functional groups.