6 test tubes on top of a kitchen table , on top of a piece of paper

6 test tubes on top of a kitchen table , on top of a piece of paper , each tube with a drop of Lugol, in tube 1 with a little piece of banana,in tube 2 with a little piece of potato, in tube 3 a pinch of sugar, in tube 4 a little piece of bread, in tube 5 a few grams of rice, in tube 6 a little piece of noodle , each one with its respective chemical reaction