Final answer:
The alkyl group, such as a methyl group, is the functional group that is nonpolar, hydrophobic, and found in hydrocarbon chains, matching the properties described in the question.
Step-by-step explanation:
Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical properties of those molecules.
For the specific properties described - nonpolar, hydrophobic, and found in hydrocarbon chains - the functional group that matches these characteristics is an alkyl group, such as a methyl group (-CH3).
Alkyl groups are composed entirely of carbon and hydrogen atoms and lack any electronegative atoms that might induce a polarity, making them nonpolar.
Their nonpolarity makes them hydrophobic, meaning they do not mix well with water but are soluble in nonpolar solvents.
The methyl group is a common example of an alkyl functional group that imparts these properties to a molecule.
In longer hydrocarbon chains, the nonpolar character increases, further reinforcing their hydrophobicity.
Alkyl groups, such as methyl, ethyl, propyl, and butyl, are typical examples of hydrophobic functional groups in organic chemistry.
The presence of these groups affects the solubility and reactivity of the whole molecule in biological and chemical systems.
Understanding the properties of different functional groups is essential for predicting the behavior of organic compounds, especially in biological contexts where these interactions can influence molecular structure and function.