What is a sign that a chemical change has happened? O A. A substance dissolves.
O B. Sound and heat are produced.
OC. A substance changes temperature.
O D. A change of state happens.

Which of your 24 wells had indications that a chemical reaction occurred? how were you able to tell that a chemical reaction occurred? which of your 24 wells had indications that a physical reaction occurred? how were you able to tell that a physical reaction occurred? report on both mixing and evaporation. make a general statement about whether your hypotheses were validated or rejected. must your hypotheses be correct for this to be a successful laboratory?