We could taste all the ingredients after we mixed them into the water. Since we could taste them, they must still be there. This was giving us some evidence that the stuff was still in the water even though we couldn't see each individual ingredient with our eyes.
All of our cups of water went up in weight by approximately the weight of the ingredient. This means that even though we can't see each ingredient, an increase in weight means that something has to be in the water beyond the water. While we didn't get exactly the same numbers each time, students admitted they may have measured wrong or spilled some of the ingredients.
Water Level/Stirring Test
Each of our cups of water rose to a new, higher level when we added something to it. This shows that whatever ingredient we put in takes up space and pushes the water up. It reminded us of a kid going in a bathtub and the water level rising.
With the exception of vinegar, we could see sugar, salt and citric acid under the microscope. We couldn't see them in the glasses of water when we mixed them together. This means that the water helped make the pieces small, so small in fact, that our eyes couldn't see them. We know by looking in the microscope that they're still there!
We'll be developing models to explain what happened...here are some students' initial thoughts! What do you notice that is similar about them? Different? What new questions do these models raise for you based on what we've experienced in class?