Plz i will give u brainlest plz which waste is produced by a fuel cell? a. gasoline vapors b. water c. hydrogen d. catalyst

The answer for #3 is c but i don't know why

List four observations that indicate that a chemical reaction may be taking place

Which of the following warnings would an agricultural chemist tell a farmer who wants to recycle his or her own ammonia? recycling ammonia is a difficult process that sometimes takes weeks. recycling ammonia requires a degree in biochemistry or a related field. recycling ammonia can be harmful because it is highly flammable and toxic. recycling ammonia costs too much money considering the price of the necessary chemicals.