Which of the following describes a chemical property of metal A, reacts with acid B, conducts electricity C, attracted to a magnet D, high melting point

Which of the following is an indication that a substance has undergone a chemical change? a. no new product has been formed. b. the color of the substance has not changed. c. the original constitute has not changed. d. the molecular structure has changed.

Which tool is least in predicting weather

If 2 molecules of one reactant combine with 3 molecules of another to produce 5 molecules of a product, then what is the representation of the reaction?