what are clues a chemical change has happened?
____________________________________________________________________. Clues that chemical change has happened. 1. Color change-autumn leaves, rotten banana, burnt toast. 2. Energy release-light, heat, sound. exothermic-gives off heat. endothermic-takes in heat. 3. Odor-eggs rotting or anything rotting. 4. Formation of gases-bubbles in antacids, vinegar and baking soda (mini-volcano). 5.