Which of the following is an example of the refraction of light? a. light transforms a substance through absorption. b. light passes through an object unchanged. c. light bounces off of an object's surface. d. light bends as it passes from one medium into another.

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.