Is mixing sodium hydrogen carbonate and hydrochloric acid a physical or chemical change

How do scientists think that gravity affected the formation of our solar system?

Compare and contrast physical changes with chemical changes.

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?