Which one of the following is a balanced equation? a. 2ca (s) + o2 (g) → 2cao (s) b. 6ca (s) + 2o2 (g) → 6cao (s) c. 4ca (s) + o2 (g) → 2cao (s) d. 6ca (s) + 4o2 (g) → 2cao (s)

What effect would average population growth have on land usage? a. urban use of land would rise to more than 30 percent of available land. b. industrial use of land would rise to more than 30 percent of available land. c. the percentage of available land used as cropland would stay the same. d. cropland would fall to about 10 percent of available land.

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.

If a straight-chain hydrocarbon is a gas at room temperature, how many carbon atoms will it have? a. 6 carbon atoms b. 12 carbon atoms c. 24 carbon atoms d. 3 carbon atoms