Identify what type of reaction each of the following is - synthesis (S), decomposition (D), combustion (C), single-displacement (SD), or double-displacement (DD). Note: one of the
problems below is NOT a chemical change it’s a physical change

The famous scientist galileo galilei did several experiments with sloping planes, which he rolled metal balls down so that he could study motion. by changing the slope, he could study how the speed at which the ball rolled was affected. what was the independent variable in galileo's experiment? a. the speed of the ball b. the slope of the plane c. whether the ball moved d. what the ball was made of

Match each statement with the state of matter it describes

Which best describes the activation energy of a chemical reaction? a. the combined energy of all the reactants b. the amount of energy required for a reaction to occur c. the difference in energy between products and reactants d. the potential energy stored in the bonds of reactants and products