Here's why:
* Contact: Diffusion requires molecules to move from one region to another. This movement can only happen if the two substances are physically touching.
* Concentration Gradient: Diffusion is driven by the natural tendency of molecules to move from an area of high concentration to an area of low concentration. This difference in concentration is called a concentration gradient.
In simpler terms: Imagine you have a drop of food coloring in a glass of water. The food coloring is highly concentrated in the drop. As time passes, the food coloring molecules will spread out and move into the areas of the water where there is less food coloring. This movement is diffusion.
Important Note: The rate of diffusion is influenced by factors like temperature, size of the molecules, and the type of medium the molecules are diffusing through.
