For Grade 9A πΏπ§. πΏπͺππ showed the students 2 examples for chemical reaction using two experiments. The first one was (π©ππ ππ‘ππ₯πππ£π©βπ¨ π©π€π€π©ππ₯ππ¨π©π), it is an example of exothermic reaction and gas production, the 2nd experiment was about color change and the change of state of matter. By using solid iodine, the students had the unique opportunity to observe the change of color from silver to purple as a clue for chemical reaction.