The distinction between diffusion and osmosis is not clear to many students. Observing coloured particles (such as food dye) diffuse in water shows direct evidence of diffusion, but the movement of water particles is not so easily observed. This demonstration prepares students for an understanding of osmosis, the diffusion of water across a selectively permeable membrane. Students have been seen diffusion, the movement of particles in from an area of high concentration to areas of low concentration. This demonstration allows students to observe the movement of water to an area of low concentration.
Categories: Teacher Demonstration
This demo demonstrates the greenhouse effect by comparing the air temperature of a room with the air temperature inside a clear plastic bag containing black construction paper. The bag models the... read more
In this demonstration, students observe what happens to activated glow sticks when they are submerged in water at three different temperatures: cold, room temperature, and hot. Students will use... read more