Science Lab Project

Today was a fun day at science class. We did a lab focusing on diffusion and osmosis. 
Me, and my group took a beaker and filled it with water, then added it to the plastic bag, 
that was filled with starch. Then we tied a knot on  the bag and sealed it tightly. Again 
we filled the beaker, but this time the teacher put a few drops of iodine. Next we put the 
bag in the iodine water, and later took it out, and saw it was purple. Even though the bag 
was closed, the iodine molecules were so small they got inside and turned the water purple.