When a drop of food coloring enters the water, it begins to disperse and spread throughout the water until it evenly colors the entire liquid. This process occurs due to diffusion.
Understanding Diffusion
Diffusion is the net movement of anything (for example, atoms, ions, molecules) from a region of higher concentration to a region of lower concentration. This movement is driven by the random motion of molecules.
- Random Movement: Water molecules are constantly moving randomly. These movements cause the food coloring molecules to also move randomly.
- Concentration Gradient: Initially, the food coloring is highly concentrated in the drop. This creates a concentration gradient between the drop and the surrounding water.
- Dispersion: Due to the random motion, the food coloring molecules move from the area of high concentration (the drop) to the area of low concentration (the rest of the water).
- Equilibrium: This process continues until the food coloring is evenly distributed throughout the water, reaching a state of equilibrium where the concentration is uniform.
Visual Example: Food Coloring Spreading
Imagine the food coloring as tiny particles. When the drop enters the water:
- The concentrated food coloring sits as a dense area in the clear water.
- The water molecules bombard the food coloring molecules, causing them to move.
- The food coloring molecules begin to spread out away from the initial concentrated drop.
- The color becomes increasingly lighter and more evenly distributed as the process continues.
- Eventually, the entire glass of water becomes uniformly colored.
The food coloring doesn't move purposefully; it's simply bumped around by the water molecules until it is equally distributed.
