Answer:
A drop of food coloring spreads out into a glass of water.
The smell of fresh-baked cookies starts from the kitchen and moves to the rest of the house.
The air freshener that you sprayed in the living rooms spreads out.
Step-by-step explanation:
A difference in concentration of molecules in physical space is called a concentration gradient. An easy to understand example from everyday life is the application and subsequent fading of perfume or aftershave scent.