👉 A fluid, in the context of changing over time, refers to a substance that can flow and take the shape of its container. Initially, a fluid might appear as a clear, uniform liquid, but as time progresses, it undergoes various transformations. It can transition from a liquid to a gas through evaporation, where molecules gain enough energy to break free from the liquid's surface. Conversely, if the fluid cools, it can condense back into a liquid, reversing this process. Additionally, fluids can experience changes in viscosity, becoming thicker or thinner depending on temperature and pressure. In some cases, fluids can even mix with other substances, altering their composition and properties. These transformations highlight the dynamic nature of fluids, constantly adapting to their environment while maintaining their fundamental characteristic of flowing and reshaping.
