Final answer:
An ingredient that is compatible with both water and oil is called an emulsifying agent. Emulsifying agents have a polar end that can interact with water and a nonpolar end that can interact with oil, allowing them to bring the two substances together and create a stable mixture.
Step-by-step explanation:
An ingredient that is compatible with both water and oil is called an emulsifying agent. Emulsifying agents have a polar end that can interact with water and a nonpolar end that can interact with oil, allowing them to bring the two substances together and create a stable mixture. Examples of emulsifying agents include egg yolk and soap. When an emulsifying agent is present, the oil and water will form an emulsion, which is a colloidal dispersion of a liquid in another liquid.