In science class, you learned that materials such as water move directly through the cell membrane by the process of diffusion. Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration. In this activity, you and your family members will see how diffusion actually happens.
- plastic container
- food coloring
- clock or stopwatch
Ask an adult to help you fill the plastic container with room-temperature water. Set the container of water on a flat, stable surface. Wait until the water stops moving. Be careful not to jiggle the container. Without touching the water or container, squeeze a drop of food coloring into the center of the water. In your notebook, draw a picture of what you see. Write down the time. Observe what happens to the drop of food coloring for 5–10 minutes.
What happened to the drop of food coloring as time passed? How long did it take for the water to become completely colored? How does this experiment demonstrate diffusion?