question below:
Which of the following is formed when two elements combine chemically?
answer below:
a compound

question below:
Which human organ system exchanges gases with the environment?
answer below:
respiratory

question below:
The students were told that the net applied force from the engine was the same for each vehicle tested. Based on this information, which vehicle had the greatest acceleration (a = F/m)?
answer below:
vehicle 1

question below:
Base your answer on the information below and on your knowledge of science. A baseball strikes the roof of a car and dents it. The paint on the roof begins to crack and chip, exposing the metal. The exposed metal on the roof rusts, eventually causing a small hole in the roof. Which event is a chemical change?
answer below:
The exposed metal rusts.