Which of the following statements correctly describes a change in matter responses
a. a chemical change is indicated when two compounds are mixed, leading to the production of gas bubbles. b. a chemical change is indicated when two compounds are mixed, leading to the production of gas bubbles. c. a physical change is indicated when two compounds are mixed and form a new substance. d. a physical change is indicated when two compounds are mixed and form a new substance. e. a chemical change is indicated when a substance undergoes a phase change from gas to a solid.