Final answer:
Fats, oils, and waxes, which are nonpolar molecules, are hydrophobic and do not mix well with water, leading to a separation into distinct layers when combined.
Step-by-step explanation:
Nonpolar molecules such as fats, oils, and waxes do not interact well with water, a polar molecule. This is due to the fact that water molecules are attracted to one another, as well as to other polar molecules and ions, through hydrogen bonding, making water hydrophilic. However, when it comes to nonpolar substances, which are hydrophobic, water molecules are more attracted to each other than to nonpolar molecules, leading to a lack of interaction. Therefore, substances like fats and oils do not dissolve in water and will separate to form different layers when mixed with water.
Water molecules also repel molecules with nonpolar covalent bonds, like fats, lipids, and oils. A simple kitchen experiment can demonstrate this: pour a teaspoon of vegetable oil, a compound formed by nonpolar covalent bonds, into a glass of water. Instead of instantly dissolving, the oil forms a distinct bead because the polar water molecules repel the nonpolar oil.