Answer:
Nonpolar side chains of amino acids tend to associate to form hydrophobic clusters usually away from the protein surface.
Explanation:
Hydrophobic interactions are defined as the relationship between the low water soluble molecules named hydrophobes and water. They contains a long chain of carbon atoms and are usually considered as a nonpolar molecules.
They occur when the non polar amino acids are associated to produce the hydrophobic clusters that are usually away from the surface of the protein.