👉 Occurred fluid, also known as effusion fluid, is a type of fluid that forms spontaneously at the boundary between two immiscible liquids when they are in equilibrium. This fluid is typically lighter than the liquid on which it forms and is composed of molecules that have more freedom to move. The most common example is the fluid that occurs when mercury (heavy) and water (light) are in contact, resulting in mercury evaporating into a layer of water vapor. This process happens because the molecules at the surface have higher kinetic energy and escape more easily, creating a continuous exchange until equilibrium is reached.
