Diffusion Investigation

Food Coloring into Water

Experimental Set-Up Corn starch solution Iodine Solution

Iodine Indicator with Foods

Basic Reaction with Iodine Indicator

Results from reaction

Adding Cornstarch to Green Water

After 24 Hours

Reaction in Teach Tank Before

Reaction in Teach Tank 24 Hours Later

Why did the iodine go in and out of the bag and other items didn’t? Why did the iodine stop going into the beaker? (After 24 hours, most of the iodine was still in the bag)

Matter Atoms Molecules Compounds

Areas of high concentration move into areas of low concentration until there is equal concentration of the substance Example: sugar cube

Examples of Diffusion Kool-aid powder poured into water Tea with sugar Smelly feet- odor travels across the room Perfume Air Freshener Tie Dye

Passive transport Materials move through the cell without using the cells energy

Osmosis Diffusion of water across the cell membrane Required no energy

Active Transport Process of using energy to move things across the cell membrane Examples that require cell’s energy to move Salt out of the cells Oxygen Carbon Dioxide Sugars

Cell size affects transport Cells have to be small in order to do their jobs; small size = greater surface area

Gobstopper Connection At the beginning of the year, we did an experiment with gobstoppers. Go back to those pages and add the explanation for the experiment

Gobstopper Explanation Color spread because of diffusion. The area next to the candy had a high concentration of sugar and dye. The water had a very low concentration, therefore the dye and sugar moved into the water