Hydrophobic

Hydrophobic describes substances that do not mix well with water. The term comes from "hydro" meaning water and "phobic" meaning fear or dislike. Hydrophobic molecules tend to avoid water because they are usually nonpolar, meaning their electrical charges are evenly distributed. This causes them to cluster together, minimizing contact with water. An example is oil, which doesn't dissolve in water and instead forms separate layers or droplets. Hydrophobic interactions are important in biological systems, such as how cell membranes are formed, with nonpolar regions within the membrane avoiding water while polar regions face outward.