This week we observed what happens when we add fizzy tablets to a mixture of water, cooking oil and food colouring. We already knew that the oil would settle on top of the water in the testtube. We also knew that the food colouring would fall slowly through the oil and mix with the water at the bottom. This week we added a fizzy vitaman C tablet into the test tube as well. The bubbles that were made when the tablet dissolved, took the colour up to the top of the test tube. The colour fizzed and moved up and down. We wondered what would happen if the water was warm, or the water was sea water. Would there be a different reaction?