6. After completing an experiment, all chemical waste should be
A. left at your lab station for the next class.
B. disposed of according to your instructor's
directions.
C. dumped in the sink.
D. taken home.

B. disposed of according to your instructor's  directions.

Explanation:

After completing an experiment all chemical waste should be disposed of according to your instructor's directions.

Chemical wastes should be carefully handled in the laboratory so as not to carelessly release them into the environment. If not properly treated and they are discharged into the environment, they can lead to serious hazards and even pollution. Contamination is another very serious problem attributed to disposing chemical waste carelessly.

Instructor's guides should be followed to dispose chemical wastes.